Add *** pm section: load pm.el integration from canonical repo
Wires the standalone Emacs package shipped from
~/.repos/project-manager/extensions/emacs/. Hooks the pm container
finder into project.el, binds C-x p P (pm-dispatch) and C-x p .
(pm-project-dispatch), and registers pm-project-dispatch as the post-
project-switch entry "PM". Initial pm-refresh runs on an idle timer
out of after-init-hook.