feat(docker): add custom image and tag env configuration (#306)

- Replace hardcoded image values with overrideable env variables
- Standardize version env var from LVA_VERSION to LVA_IMAGE_TAG
- Add new env options documentation to .env.example
- Add dev.env to gitignore
- Disable default mic noise suppression in dev compose

BREAKING CHANGE: LVA_VERSION env var replaced with LVA_IMAGE_TAG

docker-compose.yml

@@ -2,7 +2,7 @@
 services:
   # Fix permissions for wakeword_data and configuration volume
   fix-permissions:
-    image: "ghcr.io/ohf-voice/linux-voice-assistant:${LVA_VERSION:-latest}"
+    image: "${LVA_IMAGE:-ghcr.io/ohf-voice/linux-voice-assistant}:${LVA_IMAGE_TAG:-latest}"
     entrypoint: []
     command: "chown -R ${LVA_USER_ID:-1000}:${LVA_USER_GROUP:-1000} /app/local /app/configuration /app/wakewords/custom /app/sounds/custom"
     environment:
@@ -24,7 +24,7 @@ services:
   # Linux Voice Assistant
   linux-voice-assistant:
     container_name: linux-voice-assistant
-    image: "ghcr.io/ohf-voice/linux-voice-assistant:${LVA_VERSION:-latest}"
+    image: "${LVA_IMAGE:-ghcr.io/ohf-voice/linux-voice-assistant}:${LVA_IMAGE_TAG:-latest}"
     restart: unless-stopped
     network_mode: "host"
     user: "${LVA_USER_ID:-1000}:${LVA_USER_GROUP:-1000}"