Documentation for Nestri (#116)

I have made documentation for Nestri, so everybody easy can find
instructions to get started. It will also make it easier for people to
help contribute to the documentation.

The documentation is built with Nuxt3, [Docus
](https://github.com/nuxt-themes) which uses Nuxt Content.

![image](https://github.com/user-attachments/assets/b30258c3-2267-4710-b8f4-48145e7c98d0)

![image](https://github.com/user-attachments/assets/6ccad52e-b6e1-4c8d-9c0c-bc4fae0227f1)

apps/docs/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "docus-starter",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "nuxi dev",
+    "build": "nuxi build",
+    "generate": "nuxi generate",
+    "preview": "nuxi preview",
+    "lint": "eslint ."
+  },
+  "devDependencies": {
+    "@nuxt-themes/docus": "latest",
+    "@nuxt/devtools": "^1.4.1",
+    "@nuxt/eslint-config": "^0.5.6",
+    "@nuxtjs/plausible": "^1.0.2",
+    "@types/node": "^20.16.5",
+    "eslint": "^9.10.0",
+    "nuxt": "^3.13.1"
+  }
+}