selectrum: rework consult previews

- add `C-M-j` and `C-M-k` as preview scrolling keys
- add `consult-theme` to functions that don't get previewed
  automatically (also it works now)

modules/completion/selectrum/TODO.org

@@ -20,8 +20,6 @@ Need to get it to work for other selectrum commands such =SPC h f=.
 #+end_src
 gets us close but moves the cursor to the new screen which is undesirable.
 probable best strategy: create an ~embark-preview~ that does this, upstream it.
-** TODO ~consult-theme~ is buggy
-something to do with doom theme loading modifications
 ** TODO ripgrep height logic bad
 selectrum bug caused by file descriptors
 https://github.com/raxod502/selectrum/issues/491

modules/completion/selectrum/config.el

@@ -96,9 +96,11 @@
         consult-line-numbers-widen t
         consult-async-input-debounce 0.5
         consult-async-input-throttle 0.8)
-  (setf (alist-get #'consult-bookmark consult-config) (list :preview-key (kbd "C-SPC")))
-  (setf (alist-get #'consult-recent-file consult-config) (list :preview-key (kbd "C-SPC")))
-  (setf (alist-get #'consult--grep consult-config) (list :preview-key (kbd "C-SPC"))))
+  (mapc
+   (lambda (x) (setf
+                (alist-get x consult-config)
+                (list :preview-key (list (kbd "C-SPC") (kbd "C-M-j") (kbd "C-M-k")))))
+   '(consult-bookmark consult-recent-file consult--grep consult-theme)))
 
 (use-package! consult-flycheck
   :when (featurep! :checkers syntax)