The package documentation system no longer relies on README and
requirements.txt to setup an ad hoc Sphinx build.

This is the templated boilerplate for package documentation. The
manifest declares lsst.verify **module** documentation and verify
**package** documentation directories.

This is a sweep through the docstrings to fix obvious errors and typos.
The fixes are mostly to add missing docstrings, improve code links, and
fix formatting issues.