Add recma-module-to-function to list of plugins

Closes GH-2605.

Reviewed-by: Christian Murphy <christian.murphy.42@gmail.com>
Reviewed-by: Titus Wormer <tituswormer@gmail.com>

Author: remcohaszing

docs/docs/extending-mdx.mdx

@@ -87,6 +87,8 @@ See also the [list of remark plugins][remark-plugins],
 * [`remcohaszing/recma-nextjs-static-props`](https://github.com/remcohaszing/recma-nextjs-static-props)
   — generate [`getStaticProps`](https://nextjs.org/docs/basic-features/data-fetching/get-static-props)
   exposing top level identifiers in Next.js
+* [`remcohaszing/recma-module-to-function`](https://github.com/remcohaszing/recma-module-to-function)
+  — convert a module into a function body
 * [`remcohaszing/rehype-mdx-code-props`](https://github.com/remcohaszing/rehype-mdx-code-props)
   — interpret the code `meta` field as JSX props
 * [`remcohaszing/rehype-mdx-import-media`](https://github.com/remcohaszing/rehype-mdx-import-media)