New docs site (#2521)

* initial docs

* more docs work

* Update readme + add license

* update frontend GH action

apps/docs/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "@modrinth/docs",
+  "type": "module",
+  "version": "0.0.1",
+  "scripts": {
+    "dev": "astro dev",
+    "start": "astro dev",
+    "build": "astro check && astro build",
+    "preview": "astro preview",
+    "astro": "astro"
+  },
+  "dependencies": {
+    "@astrojs/check": "^0.9.3",
+    "@astrojs/starlight": "^0.26.3",
+    "@modrinth/assets": "workspace:*",
+    "astro": "^4.10.2",
+    "sharp": "^0.32.5",
+    "starlight-openapi": "^0.7.0",
+    "typescript": "^5.5.4"
+  }
+}