Kindly asking feature for bookmarking file itself in the explorer side bar

[Raynchowkw]

My need is to label files which I have gone over and made update according to new development cycle.
I know git can keep track of unsaved changed files, but sometimes I don't use git for small program.
If bookmarks can label file, that would be great.
Otherwise, I will just add a label inside each file and use the bookmarks sidebar to keep track of it.
Thanks.