Configured pydocstyle for the trainer, callbacks, loggers, optimizers, and utils.

[ravi-mosaicml]

This PR enables the pydocstyle pre-commit hook for most of the codebase. Docstrings were brought up to compliance so they would pass the pydocstyle check.

• The main changes involved ensuring summary docstring lines were indeed just one line, that they ended with periods, and that there were no blank lines between the end of the docstring and the start of the function.
• Added docstrings for missing arguments that were identified.
• (Coming along for the ride): Remove calls to trainer.engine.close, as now close() is invoked automatically in __del__ as part of Multiple calls to Trainer.fit() #948

Model, dataset, and algorithm docstrings will be addressed in future PRs.

[eracah]

This PR is obv very large and mostly contains routine docstring edits. I won't look at each one; I will trust that pydoctest does what it claims to do. Any diffs that do other things that we should take special look at in this PR? Like the pre-commit config or anything else?

[ravi-mosaicml]

This PR is obv very large and mostly contains routine docstring edits. I won't look at each one; I will trust that pydoctest does what it claims to do. Any diffs that do other things that we should take special look at in this PR? Like the pre-commit config or anything else?

I know it's a bunch of files, but it would be super helpful if you could double check that there aren't any unintentional changes from a sloppy merge that I might have done (e.g. remove new functionality). Let me update it against the latest dev.

[A-Jacobson]

there are a few changes in here that are unrelated to docs. I've flagged them so you can confirm you intend them to be in here.

Also fixed a few typos and made some grammar suggestions. Most are a matter of opinion, you don't have to accept them.

Other than that LGTM, thanks for taking the time to clean this stuff up!

[Averylamp]

lgtm, small nits