Add mod documentation in seven languages

manifest.json

@@ -3,7 +3,7 @@
   "name": "Audio Engine",
   "version": "1.0.0",
   "author": "ct",
-  "description": "Engine audio subsystem: IAudioService implementation (Music/SFX/Ambient buses), the auto-advancing music player and the audio factories (music, sounds, playlists). Replaces the former Core/Audio autoloads — the AudioModInitializer adds nodes named AudioService and MusicPlayer to the scene tree root on the boot Scenes phase, so /root/AudioService keeps resolving.",
+  "description": "Audio engine: scene music, sound effects and ambience on separate buses with their own volume, and a music player that follows the current scene.",
   "category": "engine, library",
   "sources": [
     "src/**/*.cs"