Update docusaurus to 2.0.0-beta.9

Author: lwronski

website/package.json

@@ -14,13 +14,13 @@
     "write-heading-ids": "docusaurus write-heading-ids"
   },
   "dependencies": {
-    "@docusaurus/core": "2.0.0-beta.8",
-    "@docusaurus/preset-classic": "2.0.0-beta.8",
-    "@mdx-js/react": "^1.6.21",
+    "@docusaurus/core": "2.0.0-beta.9",
+    "@docusaurus/preset-classic": "2.0.0-beta.9",
+    "@mdx-js/react": "^1.6.22",
     "clsx": "^1.1.1",
     "docusaurus-plugin-sass": "^0.2.1",
-    "react": "^17.0.1",
-    "react-dom": "^17.0.1",
+    "react": "^17.0.2",
+    "react-dom": "^17.0.2",
     "react-player": "^2.9.0",
     "sass": "^1.42.1"
   },