Enhanced tp_doc strings for both layer types to include:
- What happens when grid_size=None (inherits from parent Grid)
- That layers are created via Grid.add_layer() rather than directly
- FOV-related methods for ColorLayer
- Tile index -1 meaning no tile/transparent for TileLayer
- fill_rect method documentation
- Comprehensive usage examples
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
