feat(runfiles): Add static methods to Runfiles class to simplify interface

[UebelAndre]

With this change we allow for more ergonomic creation of the runfiles
object and using type annotations:

from python.runfiles import Runfiles

def main() -> None:
    runfiles: Runfiles | None = Runfiles.Create()

Furthermore, the docs have been updated to describe pulling runfiles
library directly from rules_python to avoid the complexity of needing
to setup pip_parse to use this behavior.

[UebelAndre]

cc @aignas is this one ok as well?

[aignas]

I'll have a look at it later early next week.

[aignas]

I personally don't like the Create method, because it smells of bad polymorphism design, but at the same time i think that allowing easy type annotations is a not win. @rickeylev, what do you think?

[UebelAndre]

If there's no blockers is this something that could be merged soon? I think it'd be good to consolidate the import paths for pypi releases and rules_python releases but that should be a separate change.

cc @aignas @rickeylev

[aignas]

@UebelAndre, just came back from holiday.

Sorry for being pedantic, but as per the PR template todo checklist, could you please add a CHANGELOG.md and make the PR description more like a commit message? Otherwise the change looks good to me.

[UebelAndre]

@UebelAndre, just came back from holiday.

Sorry for being pedantic, but as per the PR template todo checklist, could you please add a CHANGELOG.md and make the PR description more like a commit message? Otherwise the change looks good to me.

What do you mean "more like a commit message"?

If you modify the description to your liking I can make sure my future PRs follow this pattern.

[aignas]

Condensed the message slightly and used passive voice and reworded to sound more like what is being added/changed with the commit rather than what is proposed. Thanks a lot for the improvements to rules_python!