Add ability to select files to be changed

I have a case where I generate a lot of files but want to commit just a few of them. It will be helpful if you provide the ability to pass files to be added.

Sorry for a very long answer.
This looks for me like a wrong usage of .gitignore instead of relaying it on commit action.
Adding it would require adding whitelist, but also a blacklist.
What would be the expected effect and general use for all?