Update docusaurus to 2.3.1 (#2423)

## Description

When I built the docs, Docusaurus said:
```
   ╭──────────────────────────────────────────────────────────────────────────────────────────╮
   │                                                                                          │
   │                              Update available 2.0.1 → 2.3.0                              │
   │                                                                                          │
   │     To upgrade Docusaurus packages with the latest version, run the following command:   │
   │          `yarn upgrade @docusaurus/core@latest @docusaurus/preset-classic@latest`        │
   │                                                                                          │
   ╰──────────────────────────────────────────────────────────────────────────────────────────╯
```

I thought it would be smart to listen, so there's the PR 😄.

## Test plan

Check the docs

Author: j-piasecki

docs/package.json

@@ -14,8 +14,8 @@
     "write-heading-ids": "docusaurus write-heading-ids"
   },
   "dependencies": {
-    "@docusaurus/core": "^2.0.1",
-    "@docusaurus/preset-classic": "^2.0.1",
+    "@docusaurus/core": "^2.3.1",
+    "@docusaurus/preset-classic": "^2.3.1",
     "@mdx-js/react": "^1.6.21",
     "classnames": "^2.3.1",
     "clsx": "^1.1.1",