bug#50499: 28.0.50; project.el: Root of current project

[Augusto Stoffel]

I guess most uses of `project-root' will be of the form

    (when-let ((p (project-current)))
       (project-root p))

Or at least this is true in the case of an user who is quickly defining
a shortcut command in their config.

Wouldn't it make sense to make the PROJECT argument of `project-root'
optional, giving the above result when omitted?