Address documentation/docstring TODOs

[dwinston]

Related subsystem(s)

• Runtime API (except the Minter)
• Minter
• Dagster
• Project documentation (in the docs directory)
• Translators (metadata ingest pipelines)
• MongoDB migrations
• Other

Testing

• I tested these changes (explain below)
• I did not test these changes

I tested these changes by...

Documentation

• I have not checked for relevant documentation yet (e.g. in the docs directory)
• I have updated all relevant documentation so it will remain accurate
• Other (explain below)

Maintainability

• Every Python function I defined includes a docstring (test functions are exempt from this)
• I used black to format all the Python files I created/modified
• The PR title is in the imperative mood (e.g. "Do X") and not the declarative mood (e.g. "Does X" or "Did X")

[eecavanna]

Thank you, @dwinston! I just saw this PR here (while looking for a different one). I think this will make it easier for people to navigate and maintain the code base.