chore: README: various small tweaks (#651)

- Change "What is it" heading to "What it is", as it's not a question
- Expand SSR acronym
- Slightly reword some passages for clarity

Author: waldyrious

docs/README.md

@@ -2,11 +2,11 @@
 
 > A magical documentation site generator.
 
-## What is it
+## What it is
 
-docsify generates your documentation website on the fly. Unlike GitBook, it does not generate static html files. Instead, it smartly loads and parses your Markdown files and displays them as website. All you need to do is create an `index.html` to start and [deploy it on GitHub Pages](deploy.md).
+docsify generates your documentation website on the fly. Unlike GitBook, it does not generate static html files. Instead, it smartly loads and parses your Markdown files and displays them as a website. To start using it, all you need to do is create an `index.html` and [deploy it on GitHub Pages](deploy.md).
 
-See the [Quick start](quickstart.md) for more details.
+See the [Quick start](quickstart.md) guide for more details.
 
 ## Features
 
@@ -17,16 +17,16 @@ See the [Quick start](quickstart.md) for more details.
 - Useful plugin API
 - Emoji support
 - Compatible with IE10+
-- Support SSR ([example](https://github.com/docsifyjs/docsify-ssr-demo))
+- Support server-side rendering ([example](https://github.com/docsifyjs/docsify-ssr-demo))
 
 ## Examples
 
-Check out the [Showcase](https://github.com/docsifyjs/docsify/#showcase) to docsify in use.
+Check out the [Showcase](https://github.com/docsifyjs/docsify/#showcase) to see docsify in use.
 
 ## Donate
 
 Please consider donating if you think docsify is helpful to you or that my work is valuable. I am happy if you can help me [buy a cup of coffee](https://github.com/QingWei-Li/donate). :heart:
 
 ## Community
 
-Users and development team are in the [Gitter](https://gitter.im/docsifyjs/Lobby).
+Users and the development team are usually in the [Gitter chat room](https://gitter.im/docsifyjs/Lobby).