Initial RS-UV3A Starlight documentation site

Documentation for the HobbyPCB RS-UV3A tri-band FM transceiver board
covering 2m, 1.25m, and 70cm amateur radio bands.

Structure:
- Getting Started: quick start, connections, serial setup
- Guides: voice, packet/APRS, beacons, repeater/satellite, firmware
- Reference: specs, 66 serial commands, connector pinouts, hw revisions
- Accessories: RS-UVPA 5W power amplifier

Features:
- Ham radio green theme for readability
- Full command reference with categorization
- Searchable via Starlight/Pagefind
- Mobile responsive

package.json

@@ -0,0 +1,17 @@
+{
+  "name": "rs-uv3-docs",
+  "type": "module",
+  "version": "0.0.1",
+  "scripts": {
+    "dev": "astro dev",
+    "start": "astro dev",
+    "build": "astro build",
+    "preview": "astro preview",
+    "astro": "astro"
+  },
+  "dependencies": {
+    "@astrojs/starlight": "^0.37.4",
+    "astro": "^5.6.1",
+    "sharp": "^0.34.2"
+  }
+}