Synchronize the cava module man page with the current implementation:
- Fix scdoc table syntax (correct header/body cell prefixes)
- Add missing Waybar-side options: format-icons, vertex_shader, fragment_shader
- Remove options not consumed by the module (data_format, raw_target)
- Clarify option scope: raw-only, GLSL-only, and cava-config-only settings
- Update descriptions to match backend behavior:
- ascii_range is derived from format-icons length
- bar_height is ignored by Waybar
- bar_delimiter is used for raw output
- Polish grammar, tighten structure, and fix example filenames
- Refresh STYLE and FRONTENDS sections to match the actual source