PR Summary

Docstring cleanups:

• (Half)-sentences should always end with a period (PEP-257: The docstring is a phrase ending in a period; and numpydoc style)
• pydocstyle D200: One-line docstring should fit on one line with quotes.
• No trailing blank lines in docstrings.
• Blank line after class docstring. (PEP-257: Insert a blank line after all docstrings (one-line or multi-line) that document a class -- generally speaking, the class's methods are separated from each other by a single blank line, and the docstring needs to be offset from the first method by a blank line.)
• Some other misc cleanups.