fix: Add config.yml support for Docker deployment

Mount config.yml into Docker container and provide example template.

Changes:
- Mount config.yml as read-only volume in docker-compose.yml
- Create config.example.yml template for users
- Add config.yml to .gitignore (contains sensitive settings)
- Update README.md with config file setup instructions

Fixes 'Config file not found' error in Docker deployment.

Users should:
1. Copy config.example.yml to config.yml
2. Edit config.yml with their settings
3. Run docker compose up -d

.gitignore

@@ -37,6 +37,9 @@ env/
 .env
 .env.local
 
+# Configuration (contains sensitive data)
+config.yml
+
 # Data
 data/
 *.db