help: assigning categories to existing commands
I'm separating this into its own commit so people can bikeshed over the actual
categorization (vs the support for categories). These categories are based on
the help implementation we've been using internally at Google, and have had
zero complaints.
Differential Revision: https://phab.mercurial-scm.org/D5067
To run the tests, do:
cd tests/
python run-tests.py
See https://mercurial-scm.org/wiki/WritingTests for
more information on writing tests.