lang/emacs-lisp: restore flycheck in elisp buffers

However, with `emacs-lisp-checkdoc` disabled and `emacs-lisp`
significantly gimped.

byte-compile-warnings may need to be adjusted to allow for *some*
warnings.

Also, reformat emacs-lisp-mode hooks

modules/lang/emacs-lisp/autoload.el

@@ -122,12 +122,27 @@ if it's callable, `apropos' otherwise."
           ("Types" "^\\s-*(\\(cl-def\\(?:struct\\|type\\)\\|def\\(?:class\\|face\\|group\\|ine-\\(?:condition\\|error\\|widget\\)\\|package\\|struct\\|t\\(?:\\(?:hem\\|yp\\)e\\)\\)\\)\\s-+'?\\(\\(?:\\sw\\|\\s_\\|\\\\.\\)+\\)" 2))))
 
 ;;;###autoload
-(defun +emacs-lisp|disable-flycheck-maybe ()
-  "Disable flycheck-mode if in emacs.d."
+(defun +emacs-lisp|reduce-flycheck-errors-in-emacs-config ()
+  "Remove `emacs-lisp-checkdoc' checker and reduce `emacs-lisp' checker
+verbosity when editing a file in `doom-private-dir' or `doom-emacs-dir'."
   (when (and (bound-and-true-p flycheck-mode)
              (eq major-mode 'emacs-lisp-mode)
              (or (not buffer-file-name)
                  (cl-loop for dir in (list doom-emacs-dir doom-private-dir)
                           if (file-in-directory-p buffer-file-name dir)
                           return t)))
-    (flycheck-mode -1)))
+    (add-to-list (make-local-variable 'flycheck-disabled-checkers)
+                 'emacs-lisp-checkdoc)
+    (set (make-local-variable 'flycheck-emacs-lisp-check-form)
+         (concat "(progn "
+                 (prin1-to-string
+                  `(progn
+                     (load ,user-init-file t t)
+                     (defmacro map! (&rest _))
+                     (setq byte-compile-warnings
+                           '(obsolete cl-functions
+                             interactive-only make-local mapcar
+                             suspicious constants))))
+                 " "
+                 (default-value 'flycheck-emacs-lisp-check-form)
+                 ")"))))

modules/lang/emacs-lisp/config.el

@@ -48,12 +48,16 @@ This marks a foldable marker for `outline-minor-mode' in elisp buffers.")
     #'(;; 3rd-party functionality
        auto-compile-on-save-mode
        outline-minor-mode
+       ;; fontificiation
+       rainbow-delimiters-mode
+       highlight-quoted-mode
        ;; initialization
        +emacs-lisp|extend-imenu))
 
   ;; Flycheck's two emacs-lisp checkers produce a *lot* of false positives in
-  ;; emacs configs, so disable it when you're editing them
-  (add-hook 'flycheck-mode-hook #'+emacs-lisp|disable-flycheck-maybe)
+  ;; emacs configs, so we disable `emacs-lisp-checkdoc' and reduce the
+  ;; `emacs-lisp' checker's verbosity.
+  (add-hook 'flycheck-mode-hook #'+emacs-lisp|reduce-flycheck-errors-in-emacs-config)
 
   ;; Special fontification for elisp
   (font-lock-add-keywords
@@ -64,8 +68,6 @@ This marks a foldable marker for `outline-minor-mode' in elisp buffers.")
            (when +emacs-lisp-enable-extra-fontification
              `((+emacs-lisp-highlight-vars-and-faces . +emacs-lisp--face)))))
 
-  (add-hook! 'emacs-lisp-mode-hook #'(rainbow-delimiters-mode highlight-quoted-mode))
-
   ;; Recenter window after following definition
   (advice-add #'elisp-def :after #'doom*recenter)