Return value from help command

Even though this command will call sys.exit, we still
want it to return, if nothing else for clarity.

This also helps for testing purposes as well.

I added a start of tests for docs to make sure that we don't
break help output in the future.  I plan on greatly expanding these
tests as needed.
Fix lint warnings

No functional changes.
Add tests for JSON and shorthand syntax docs
Add tests for argument/command orderering

To get these tests to pass, I added back the OrderedDict
usage that was missing.  This also requires a bug fix
to bcdoc for all the tests to pass.
Add test for examples section in operations help
Add rendered doc content to failure message
Make use of the start_index when searching for the args in the string.