Implement task add and task move subcommands for managing tasks in TASKS.md.
task add <slug> <title> [--section <section>]:
- Adds a task to the specified section (default: Inbox)
- Valid sections: Inbox, Proximo, En curso, Bloqueado, En espera, Hecho
- Creates section if it doesn't exist
task move <slug> <task_title> <to_section>:
- Searches for task by title across all sections
- Moves task to destination section
- Marks task as completed ([x]) when moved to Hecho
- Updates checkbox state based on destination
Includes parsing and building functions for TASKS.md with:
- Section normalization (English to Spanish names)
- Merge support for duplicate normalized sections
- Standard section ordering
Uses app.add_typer to register task subcommand group.