message: docs: add react-icons note for social buttons icons
diff: @@ -168,6 +168,10 @@ use their buttons via the `colorScheme` prop.
  </HStack>
  ```
  +The Facebook and Twitter icons in the above example are available from
  +[`react-icons`](https://react-icons.netlify.com/#/) as `FaFacebook` and
  +`FaTwitter`, found in the `react-icons/fa` import.
  +
  ### Grouping Buttons
  You can use the `Stack` or `ButtonGroup` component to group buttons. When you
  