Tyro

dcargs.parse()` has been renamed `dcargs.cli()`.
Instead of just dataclasses, we now support general typed callables: functions, standard classes, attrs, etc.

Docstring and helptext improvements:
- Suppress TypeError from docstring parser in Jupyter notebooks.
- Comment parsing is now more robust; it also now supports grouping,
where the same comment is associated with multiple fields.
- Printed defaults, particularly for sequence types (lists, tuples,
sets), are now more consistently formatted.

Improved readability of `--help`. We now group arguments and generate comment/docstring-based helptext for nested dataclasses.

Redesigned how annotations are parsed and used to instantiate fields; an iterative process is now recursive.

This is simpler, enables more informative error messages, and makes containers slightly more robust; supported annotations now include sequence types containing literals or enums (eg `List[Literal[0, 1, 2, 3]]` or `Tuple[SomeEnum, SomeEnum, SomeEnum]`).

Helptext + default value improvements!