Add support for .gitignore

[juanmah]

In my project, I have some files and folders excluded to sync with git.
In them, there are some python files which SHALL be ignored also for pip-missing-reqs.

Currently, I've these files/folders excluded with --ignore-file=.

It would be great that pip-missing-reqs could use .gitignore (with an optional parameter).
In instance, pip-missing-reqs --use-gitignore.

[adamtheturtle]

Thanks @juanmah for the suggestion. Is this something you have seen in other linters or similar tools? I am not familiar with this and am looking for inspiration and also to check my instinct that this would be a bit odd.

[juanmah]

Yes. For example, I use vscode and the search function has an option to ignore files and folders that are in .gitignore.

[MrMino]

@adamtheturtle I think the best example of this idea can be found in ripgrep, which by default uses .ignore / .gitignore to exclude files from search.