feat(lib): add :depth support to add-hook!
feat(lib): add :depth support to add-hook!

The semantics of add-hook's APPEND argument changed in 27.1: it was
replaced with DEPTH, which controls its exact order of the hook (and is
respected every time a function is added to a hook, throughout its
lifetime).

Includes a general refactor for add-hook! too.

hlissner/.emacs.d,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/.emacs.d,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/.emacs.d,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs,hlissner/doom-emacs