Add quotes to path variable for add_path subcommand

[brucetony]

I ran into issues getting the git functionality to work on Windows. At first, I was going to alter the package to use pathlib, but I found a much simpler fix to get it to work on both Windows and Unix systems by simply wrapping the filepath in quotes in the subcommand.

[mbarkhau]

Very nice. Thanks for the PR :heart: