fix: indicate whether an argument is optional in the help command

[myarmolinsky]

Makes the help command args() function distinguish optional arguments

[mdonnalley]

@myarmolinsky Thanks for taking the take to submit a PR.

Per the spec, both upper case and angle brackets are valid ways of specifying required arguments:

https://docopt.readthedocs.io/en/0.4.0/#usage-pattern-format

<arguments>, ARGUMENTS. Arguments are specified as either upper-case words, e.g. my_program.py CONTENT-PATH or words surrounded by angular brackets: my_program.py .

Because of that I'm not inclined to accept the PR unless there's strong community support for it. However, I would accept a PR that adds an configuration option to enable angle brackets - if that's something you're interested in doing.

[myarmolinsky]

Understood @mdonnalley , thank you for the information and for evaluating this PR. We will consider PRing the configuration option. In the meantime, would you consider the second commit (without the <> part)? The help command does not currently distinguish optional from required if I am not mistaken, so it would still be beneficial in my opinion

[mdonnalley]

@myarmolinsky Thanks for point that out - I missed that in the PR description.

Yeah, I'm happy to merge that change

[myarmolinsky]

Thanks @mdonnalley , I have dropped the first commit and updated the second to only apply [], not <>

[mdonnalley]

@myarmolinsky Thanks! I'm going to merge this into a separate feature branch so that all the integration tests can run. Once those pass, I'll merge to main