Copy Path to Files and Folders

Instead of fumbling multiple commands, use `cppath` for the current directory ($PWD). Or, include a relative path to copy the absolute path to a file, i.e. `cppath README.md` or `cppath foo/bar.md`

https://github.com/g0t4/dotfiles/blob/40536f78d29fe966a89bcaef6f447979210d06ea/fish/load_last/pbcopy-specific.fish#L3-L45