Add remark-mdx-remove-expressions to MDX extensions list

Author: talatkuyuk

docs/docs/extending-mdx.mdx

@@ -107,6 +107,8 @@ See also the [list of remark plugins][remark-plugins],
   — enhance math with JavaScript inside it
 * [`ipikuka/remark-mdx-remove-esm`](https://github.com/ipikuka/remark-mdx-remove-esm)
   — remove import and/or export statements (mdxjsEsm)
+* [`ipikuka/remark-mdx-remove-expressions`](https://github.com/ipikuka/remark-mdx-remove-expressions)
+  — remove MDX expressions within curlybraces {} in MDX content
 
 {/*
   * Please use alpha sorting on **project** name!