You can use git to manage single files spread across your whole filesystem, things that you wouldn't create individual repos. for, but really want to backup / revert sometimes. This does not interfer with regular git repos. in the same file system.
First, create some bash, or similar, aliases:
alias ggit="git --git-dir=$HOME/global_git --work-tree=/"
alias ggitadd="ggit update-index --add"