Add command-line option for custom config file (#11)

[justcallmelarry]

Changes

Add a separate CLI option called --pyproject-file, based on the way flake8-black handles the same issue, ie config file type not being supported by flake8 in the first place.

Open questions/issues

• Is the config option aptly named? Should it be named something else?
• The config option completely ignores other config files, no thoughts on having it work together with a tox.ini or a in-directory pyproject.toml has been considered.

Testing

• Added unit tests to see that it works as expected
• Running locally in a monorepo to see that VSCode does in fact get the config from a subdirectory

[john-hen]

Sorry, took a while to merge and release. I was very busy the last few months and finally had a few days off.

I renamed the option to --toml-config in the end, somehow liked that a little better. The override behavior is fine, we can just ignore other config files in this case, the way I see it.

Thanks again, @justcallmelarry .