Merge pull request #221 from puppetlabs/PDS-436

(PDS-436) Add instructions for adding new icons

Author: vine77

packages/react-components/source/react/library/icon/Icon.md

@@ -124,6 +124,13 @@ const Renderer = () => {
 <Renderer />;
 ```
 
+## Adding icons
+
+1. _Design_: Create a new icon following the checklist and naming conventions on the [Iconography Foundations](#/Foundations/Iconography) page.
+2. _Engineering_: Run the SVG through [svgo](https://github.com/svg/svgo) to minify and remove redundant data.
+3. _Engineering_: Strip out the wrapping `svg` element, usually (but not always) leaving just a `path`.
+4. _Engineering_: Add the icon to [icons.js](https://github.com/puppetlabs/design-system/blob/master/packages/react-components/source/react/library/icon/icons.js), specifying the icon name and native SVG sizes (usually "medium" for 16px but optionally also "tiny" for 8px, "small" for 12px, or "large" for 24px).
+
 ## Related
 
 - [Button](#/React%20Components/Button) : buttons are able to render an icon as part of the component