General refactor of Doom core

- Code reduction and refactor across the board (cull unneeded minor
  advise, hooks and hacks or update them)
- Revise outdated comments and docstrings
- Reorganize core autoload libraries
- Remove large file check (Emacs already has a built-in one, which we
  augment to be even more performant when it does kick in)
- helpful.el can now be disabled completely through package!

modules/config/default/+evil-bindings.el

@@ -600,14 +600,14 @@
         :desc "Find file in project"        "/"   #'projectile-find-file
         :desc "Find file in other project"  "?"   #'doom/find-file-in-other-project
         :desc "Browse emacs.d"              "E"   #'+default/browse-emacsd
-        :desc "Browse private config"       "P"   #'+default/browse-config
+        :desc "Browse private config"       "P"   #'doom/open-private-config
         :desc "Recent project files"        "R"   #'projectile-recentf
         :desc "Delete this file"            "X"   #'doom/delete-this-file
         :desc "Find other file"             "a"   #'projectile-find-other-file
         :desc "Open project editorconfig"   "c"   #'editorconfig-find-current-editorconfig
         :desc "Find directory"              "d"   #'dired
         :desc "Find file in emacs.d"        "e"   #'+default/find-in-emacsd
-        :desc "Find file in private config" "p"   #'+default/find-in-config
+        :desc "Find file in private config" "p"   #'doom/find-file-in-private-config
         :desc "Recent files"                "r"   #'recentf-open-files
         :desc "Save file"                   "s"   #'save-buffer
         :desc "Sudo find file"              "S"   #'doom/sudo-find-file

modules/config/default/autoload/default.el

@@ -34,18 +34,6 @@
 (defun +default/find-in-notes ()
   (interactive) (doom-project-find-file org-directory))
 
-;;;###autoload
-(defun +default/find-in-config ()
-  "Open a file somewhere in `doom-private-dir' via a fuzzy filename search."
-  (interactive)
-  (doom-project-find-file doom-private-dir))
-
-;;;###autoload
-(defun +default/browse-config ()
-  "Browse the files in `doom-private-dir'."
-  (interactive)
-  (doom-project-browse doom-private-dir))
-
 ;;;###autoload
 (defun +default/compile (arg)
   "Runs `compile' from the root of the current project.

modules/ui/doom-dashboard/config.el

@@ -66,7 +66,7 @@ Possible values:
     ("Open private configuration"
      :icon (all-the-icons-octicon "tools" :face 'font-lock-keyword-face)
      :when (file-directory-p doom-private-dir)
-     :action +default/find-in-config)
+     :action doom/open-private-config)
     ("Open user manual"
      :icon (all-the-icons-octicon "book" :face 'font-lock-keyword-face)
      :when (file-exists-p (expand-file-name "index.org" doom-docs-dir))