Add option for enable/disable enum members in docstring. (#2768)

* Add option for enable/disable enum members in docstring

* Add tests for disable enum members docstring option

* Add docstring options to documentation

* style: pre-commit fixes

* Fix typos in documentation

* Improve documentation wording

* Apply suggestions by @Skylion007

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Ralf W. Grosse-Kunstleve <rwgk@google.com>