These two are now doom/open-scratch-buffer. If you're in a project,
a (persistent) scratch buffer is opened. Otherwise, a non-persistent,
transient scratch buffer is opened.
If ARG (universal argument) is non-nil, then use the current window
instead of a new window (or popup, if feature/popup is enabled).
Also, the ex command :x[!] is improved. The BANG = open in current
window.
This is a breaking change! Update your :popup settings. Old ones will
throw errors!
Doom's new popup management system casts off its shackles (hur hur) and
replaces them with the monster that is `display-buffer-alist`, and
window parameters.
However, this is highly experimental! Expect edge cases. Particularly
with org-mode and magit (or anything that does its own window
management).
Relevant to #261, #263, #325
