change mdx from 2.x to 1.6.22

Author: HsiangNianian

package.json

@@ -16,7 +16,7 @@
   "dependencies": {
     "@docusaurus/core": "2.2.0",
     "@docusaurus/preset-classic": "2.2.0",
-    "@mdx-js/react": "^2.2.1",
+    "@mdx-js/react": "^1.6.22",
     "clsx": "^1.2.1",
     "prism-react-renderer": "^1.3.5",
     "react": "^17.0.2",