Using gitignore to ignore (but not delete) files

[Arvind Dhiman]

I have a some config files in my git repo I'd like to still exist, but be ignored. I added it to .gitignore, but git status still tells me about changes to files in that directory. I tried git rm -r --cached, but that removes it from the remote repo. How can I stop tracking changes to these files, but still allow it to exist?  What should I do?