feat: allow individual components to specify additional render modes

## Details

Request: #269

Previously the only level of control users had was what modes to perform
rendering in and what components (headings, code blocks, etc.) should be
rendered when we do this.

This is a good amount of control however some users would prefer to have
a cleaner experience in insert mode while doing a subset of the
rendering done in normal mode.

To make this possible was a decent refactor but actually not too bad
because of how information is centralized in a couple key objects.

For users the way this works is the current top level `render_modes`
value now defines the set of modes where all enabled components are
rendered. Now in addition to this each individual component has its own
`render_modes` config which can specify additional modes (or all with a
boolean) in which only these components will be rendered.

So the workflow to decide rendering is now:

- Is component enabled
- Is the current mode in the top level config
- If not check if the mode is defined in the component level configuration
- Any unmatched components are skipped

Also needed to alter the logic to decide is the current mode rendered or not.
It is now the super set of all modes defined in the top level
configuration plus any defined within components. This does not matter
for the most part but does alter the events we listen on (if a component
needs to be rendered in insert mode we need to listen to insert mode
text changes now) along with the window options we set, most importantly
the conceallevel will remain at the rendered level since this is
important for many rendering features.

Example:

```lua
require('render-markdown').setup({
    render_modes = { 'n', 'c', 't' },
    heading = { render_modes = { 'i' } },
    code = { render_modes = { 'i' } },
})
```

With this configuration all components will be rendered in `normal`,
`command`, and `terminal` modes, additionally headings and code blocks
will be rendered in `insert` mode, but no others.

The default value for every component's `render_modes` is set to
`false`, which is equivalent to the empty list. This means by default
nothing is changed and we continue to render according to only the top
level `render_modes` value.

Some other minor things needed to change but nothing of particular note.

Author: MeanderingProgrammer

Diff for: README.md

@@ -173,6 +173,10 @@ Some of the more useful fields are discussed further down.
 require('render-markdown').setup({
     -- Whether Markdown should be rendered by default or not
     enabled = true,
+    -- Vim modes that will show a rendered view of the markdown file, :h mode(), for
+    -- all enabled components. Individual components can be enabled for other modes.
+    -- Remaining modes will be unaffected by this plugin.
+    render_modes = { 'n', 'c', 't' },
     -- Maximum file size (in MB) that this plugin will attempt to render
     -- Any file larger than this will effectively be ignored
     max_file_size = 10.0,
@@ -207,9 +211,6 @@ require('render-markdown').setup({
             ]],
         },
     },
-    -- Vim modes that will show a rendered view of the markdown file, :h mode()
-    -- All other modes will be unaffected by this plugin
-    render_modes = { 'n', 'c', 't' },
     anti_conceal = {
         -- This enables hiding any added text on the line the cursor is on
         enabled = true,
@@ -234,6 +235,8 @@ require('render-markdown').setup({
     latex = {
         -- Whether LaTeX should be rendered, mainly used for health check
         enabled = true,
+        -- Additional modes to render LaTeX
+        render_modes = false,
         -- Executable used to convert latex formula to rendered unicode
         converter = 'latex2text',
         -- Highlight for LaTeX blocks
@@ -252,6 +255,8 @@ require('render-markdown').setup({
     heading = {
         -- Turn on / off heading icon & background rendering
         enabled = true,
+        -- Additional modes to render headings
+        render_modes = false,
         -- Turn on / off any sign column related rendering
         sign = true,
         -- Determines how icons fill the available space:
@@ -323,6 +328,8 @@ require('render-markdown').setup({
     paragraph = {
         -- Turn on / off paragraph rendering
         enabled = true,
+        -- Additional modes to render paragraphs
+        render_modes = false,
         -- Amount of margin to add to the left of paragraphs
         -- If a floating point value < 1 is provided it is treated as a percentage of the available window space
         left_margin = 0,
@@ -332,6 +339,8 @@ require('render-markdown').setup({
     code = {
         -- Turn on / off code block & inline code rendering
         enabled = true,
+        -- Additional modes to render code blocks
+        render_modes = false,
         -- Turn on / off any sign column related rendering
         sign = true,
         -- Determines how code blocks & inline code are rendered:
@@ -391,6 +400,8 @@ require('render-markdown').setup({
     dash = {
         -- Turn on / off thematic break rendering
         enabled = true,
+        -- Additional modes to render dash
+        render_modes = false,
         -- Replaces '---'|'***'|'___'|'* * *' of 'thematic_break'
         -- The icon gets repeated across the window's width
         icon = '─',
@@ -408,6 +419,8 @@ require('render-markdown').setup({
     bullet = {
         -- Turn on / off list bullet rendering
         enabled = true,
+        -- Additional modes to render list bullets
+        render_modes = false,
         -- Replaces '-'|'+'|'*' of 'list_item'
         -- How deeply nested the list is determines the 'level', how far down at that level determines the 'index'
         -- If a function is provided both of these values are passed in using 1 based indexing
@@ -437,6 +450,8 @@ require('render-markdown').setup({
     checkbox = {
         -- Turn on / off checkbox state rendering
         enabled = true,
+        -- Additional modes to render checkboxes
+        render_modes = false,
         -- Determines how icons fill the available space:
         --  inline:  underlying text is concealed resulting in a left aligned icon
         --  overlay: result is left padded with spaces to hide any additional text
@@ -472,6 +487,8 @@ require('render-markdown').setup({
     quote = {
         -- Turn on / off block quote & callout rendering
         enabled = true,
+        -- Additional modes to render quotes
+        render_modes = false,
         -- Replaces '>' of 'block_quote'
         icon = '▋',
         -- Whether to repeat icon on wrapped lines. Requires neovim >= 0.10. This will obscure text if
@@ -486,6 +503,8 @@ require('render-markdown').setup({
     pipe_table = {
         -- Turn on / off pipe table rendering
         enabled = true,
+        -- Additional modes to render pipe tables
+        render_modes = false,
         -- Pre configured settings largely for setting table border easier
         --  heavy:  use thicker border characters
         --  double: use double line border characters
@@ -565,6 +584,8 @@ require('render-markdown').setup({
     link = {
         -- Turn on / off inline link icon rendering
         enabled = true,
+        -- Additional modes to render links
+        render_modes = false,
         -- How to handle footnote links, start with a '^'
         footnote = {
             -- Replace value with superscript equivalent
@@ -613,6 +634,8 @@ require('render-markdown').setup({
     inline_highlight = {
         -- Turn on / off inline highlight rendering
         enabled = true,
+        -- Additional modes to render inline highlights
+        render_modes = false,
         -- Applies to background of surrounded text
         highlight = 'RenderMarkdownInlineHighlight',
     },
@@ -621,6 +644,8 @@ require('render-markdown').setup({
     indent = {
         -- Turn on / off org-indent-mode
         enabled = false,
+        -- Additional modes to render indents
+        render_modes = false,
         -- Amount of additional padding added for each heading level
         per_level = 2,
         -- Heading levels <= this value will not be indented
@@ -632,6 +657,8 @@ require('render-markdown').setup({
     html = {
         -- Turn on / off all HTML rendering
         enabled = true,
+        -- Additional modes to render HTML
+        render_modes = false,
         comment = {
             -- Turn on / off HTML comment concealing
             conceal = true,
@@ -663,7 +690,7 @@ require('render-markdown').setup({
     -- if no override is provided. Supports the following fields:
     --   enabled, max_file_size, debounce, render_modes, anti_conceal, padding,
     --   heading, paragraph, code, dash, bullet, checkbox, quote, pipe_table,
-    --   callout, link, sign, indent, html, win_options
+    --   callout, link, sign, indent, latex, html, win_options
     overrides = {
         -- Overrides for different buftypes, see :h 'buftype'
         buftype = {
@@ -703,6 +730,8 @@ require('render-markdown').setup({
     heading = {
         -- Turn on / off heading icon & background rendering
         enabled = true,
+        -- Additional modes to render headings
+        render_modes = false,
         -- Turn on / off any sign column related rendering
         sign = true,
         -- Determines how icons fill the available space:
@@ -789,6 +818,8 @@ require('render-markdown').setup({
     paragraph = {
         -- Turn on / off paragraph rendering
         enabled = true,
+        -- Additional modes to render paragraphs
+        render_modes = false,
         -- Amount of margin to add to the left of paragraphs
         -- If a floating point value < 1 is provided it is treated as a percentage of the available window space
         left_margin = 0,
@@ -813,6 +844,8 @@ require('render-markdown').setup({
     code = {
         -- Turn on / off code block & inline code rendering
         enabled = true,
+        -- Additional modes to render code blocks
+        render_modes = false,
         -- Turn on / off any sign column related rendering
         sign = true,
         -- Determines how code blocks & inline code are rendered:
@@ -887,6 +920,8 @@ require('render-markdown').setup({
     dash = {
         -- Turn on / off thematic break rendering
         enabled = true,
+        -- Additional modes to render dash
+        render_modes = false,
         -- Replaces '---'|'***'|'___'|'* * *' of 'thematic_break'
         -- The icon gets repeated across the window's width
         icon = '─',
@@ -919,6 +954,8 @@ require('render-markdown').setup({
     bullet = {
         -- Turn on / off list bullet rendering
         enabled = true,
+        -- Additional modes to render list bullets
+        render_modes = false,
         -- Replaces '-'|'+'|'*' of 'list_item'
         -- How deeply nested the list is determines the 'level', how far down at that level determines the 'index'
         -- If a function is provided both of these values are passed in using 1 based indexing
@@ -963,6 +1000,8 @@ require('render-markdown').setup({
     checkbox = {
         -- Turn on / off checkbox state rendering
         enabled = true,
+        -- Additional modes to render checkboxes
+        render_modes = false,
         -- Determines how icons fill the available space:
         --  inline:  underlying text is concealed resulting in a left aligned icon
         --  overlay: result is left padded with spaces to hide any additional text
@@ -1013,6 +1052,8 @@ require('render-markdown').setup({
     quote = {
         -- Turn on / off block quote & callout rendering
         enabled = true,
+        -- Additional modes to render quotes
+        render_modes = false,
         -- Replaces '>' of 'block_quote'
         icon = '▋',
         -- Whether to repeat icon on wrapped lines. Requires neovim >= 0.10. This will obscure text if
@@ -1042,6 +1083,8 @@ require('render-markdown').setup({
     pipe_table = {
         -- Turn on / off pipe table rendering
         enabled = true,
+        -- Additional modes to render pipe tables
+        render_modes = false,
         -- Pre configured settings largely for setting table border easier
         --  heavy:  use thicker border characters
         --  double: use double line border characters
@@ -1151,6 +1194,8 @@ require('render-markdown').setup({
     link = {
         -- Turn on / off inline link icon rendering
         enabled = true,
+        -- Additional modes to render links
+        render_modes = false,
         -- How to handle footnote links, start with a '^'
         footnote = {
             -- Replace value with superscript equivalent
@@ -1229,6 +1274,8 @@ require('render-markdown').setup({
     indent = {
         -- Turn on / off org-indent-mode
         enabled = false,
+        -- Additional modes to render indents
+        render_modes = false,
         -- Amount of additional padding added for each heading level
         per_level = 2,
         -- Heading levels <= this value will not be indented