mypy

09c1fc7a - Update config file doc to match command line doc and `--help` (#7776)

Update config file doc to match command line doc and `--help` (#7776) This pull request reorganizes the command line docs, the config file docs, and the output of `--help` so they all list the options in the same order and all use the same section heading titles. It also adds a few previously undocumented flags to the docs, such as `--pretty` and several of the report generation flags. As a part of this cleanup, this PR also makes two minor changes to the flags themselves: `--custom-typing` was renamed to `--custom-typing-module` and the `--strict-optional-whitelist` flag was deprecated. Fixes #7574, #7575, #7772.