Document compatible versions of remark-parse for remark-mdx (#1517)

* Document compatible versions of remark-parse for remark-mdx (#1516)

* Update readme.md

* Update packages/remark-mdx/readme.md

Co-authored-by: JounQin <[email protected]>

Co-authored-by: John Otander <[email protected]>
Co-authored-by: JounQin <[email protected]>

Author: 3 people

packages/remark-mdx/readme.md

@@ -19,7 +19,11 @@ It’s used in [MDXjs][].
 [npm][]:
 
 ```sh
-npm install remark-mdx
+# for latest version
+npm install remark-mdx@next remark-parse
+
+# for v1
+npm install remark-mdx@1 remark-parse@8
 ```
 
 ## Use