chore(mdx support): updated README and changed CONTRIBUTING to an mdx…

… to show changes

.eslintrc.js

@@ -14,7 +14,7 @@ module.exports = {
   ],
   rules: {
     // VS Code linting will not respect the `.prettierrc` options unless injected here:
-    'prettier/prettier': ['warn', prettierrc],
+    'prettier/prettier': ['error', prettierrc],
     '@typescript-eslint/no-var-requires': 'off',
     '@typescript-eslint/no-explicit-any': 'off',
   },

README.md

@@ -67,9 +67,9 @@ Options:
 
 <!-- CODEBLOCK_END -->
 
-`markdown-inject` expands a given glob for markdown files. Then it discovers the below `CODEBLOCK` HTML comments within each markdown file, performs the appropriate action (in this case, reading another local file), and writes content back into the markdown file:
+`markdown-inject` expands a given glob for markdown files. Then it discovers the below `CODEBLOCK` HTML or MDX comments within each markdown file, performs the appropriate action (in this case, reading another local file), and writes content back into the markdown file:
 
-{/* CODEBLOCK_START_USAGE {"ignore": true} */}
+<!-- CODEBLOCK_START_USAGE {"ignore": true} -->
 
 ```
 <!-- CODEBLOCK_START {"value": ".nvmrc"} -->
@@ -79,7 +79,7 @@ Options:
 <!-- CODEBLOCK_END_USAGE -->
 
 ```
-{/* CODEBLOCK_START {"value": ".nvmrc"} -->
+<!-- CODEBLOCK_START {"value": ".nvmrc"} -->
 <!-- prettier-ignore -->
 ~~~~~~~~~~bash
 File: .nvmrc

src/md-inject.ts

@@ -114,7 +114,6 @@ const main = async (
             groupValue,
           ])
       )
-      console.log(matchGroups)
       try {
         let inputConfig: BlockInputOptions
         try {