Update packages/docs/src/pages/guides/jsx-pragma.mdx

Co-authored-by: Piotr Monwid-Olechnowicz <hasparus@gmail.com>

packages/docs/src/pages/guides/jsx-pragma.mdx

@@ -9,7 +9,7 @@ to style elements with values from your theme using the [`sx` prop][].
 
 ## What is JSX
 
-JSX is an XML-like syntax extension to JavaScript. It's a syntax sugar usually
+[JSX](https://facebook.github.io/jsx/) is an XML-like syntax extension to JavaScript. It's a syntax sugar usually
 used for [React's `jsx`](https://reactjs.org/docs/introducing-jsx.html) function. You don't need to write JSX to use React, but
 it's meant to make code more readable, especially for tree structures with
 attributes.