How To Git

I've started working on a new feature on the master branch and found hours later that I need to fix something in production, so on the original version of the branch. So ... How could I do the fix

Let’s say you’ve added by mistake a folder to your repo, you want to remove it from tracking and, of course, you are adding it to your .gitignore file. But…. pff, git continues to track it… 😟 Here