Add support for mdx (#124)

Author: Shinigami92

package.json

@@ -63,6 +63,7 @@
     "eslint-plugin-import": "~2.26.0",
     "eslint-plugin-inclusive-language": "~2.2.0",
     "eslint-plugin-jsdoc": "~39.3.6",
+    "eslint-plugin-mdx": "~2.0.2",
     "eslint-plugin-node": "~11.1.0",
     "eslint-plugin-prettier": "~4.2.1",
     "eslint-plugin-spellcheck": "~0.0.19",