Tatsu

This release uses the new procedural (nor declarative) code and model generation throughout.

The previous `codegen` remains available and unchanged for backwards compatibility.

* [walkrers] make walk_children public
* [mixins][indent] allow control over the amount of indentation
* [mixins][indent] allways trim left spacing in arguments
* [docs] deprecate declarative translation abd refactor
* [ngcodegen][model] use topological sort for order of model classes
* [tool] use `ngcodegen`
* [test] use `ngcodegen`

The undocumented `parproc` module helps to easily run parsing and translation batches in parallel.

print()` statements stranded in `buffering.py`

* [buffering] do not re.escape regex for whitespace
* [tarsu.grammar] specify missing whitespace
* [bootstrap] use generated parser that contains def for whitespace
* [buffering] keep default for whitespace but honor None correctly

* add URLs to `pyproject.toml`
* include `./examples` in source distributions

* use more `ruff` rules
* lint unit tests
* lint examples
* lint the generated parser
* make sure generated parsers and models pass `ruff`