feat(docs): Add aggregated metadata to website

Added /hardware-metadata.json to the ZMK website.
This gives external tools a way to grab all hardware metadata at once.

docs/package.json

@@ -44,7 +44,9 @@
   },
   "devDependencies": {
     "@docusaurus/module-type-aliases": "^2.0.0-beta.3",
+    "@docusaurus/types": "^2.0.0-beta.3",
     "@tsconfig/docusaurus": "^1.0.2",
+    "@types/js-yaml": "^4.0.5",
     "@types/react": "^17.0.3",
     "@types/react-helmet": "^6.1.0",
     "@types/react-router-dom": "^5.1.7",