bug#66260: 29.0.92; project.el should support copying a file path relative to the project root

[Eli Zaretskii]

> Date: Mon, 2 Oct 2023 01:44:38 +0300
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> 'C-x p w' does make sense as such, but it would be unfortunate if we 
> find a more important command later which fits the 'w' mnemonics. Maybe 
> 'C-x p W' would be a more conservative choice.

Or even "C-x p C-w".