💥 Refactor add-hook! macro & change arg order

This update may potentially break your usage of add-hook! if you pass
the :local or :append properties to it. This is how they used to work:

  (add-hook! :append 'some-mode-hook #'do-something)

Thsoe properties must now follow the hooks, e.g.

  (add-hook! 'some-mode-hook :append #'do-something)

Other changes:
- Various add-hook calls have been renamed to add-hook! because I
  incorrectly assumed `defun` always returned its definition's symbol,
  when in fact, its return value is "undefined" (so sayeth the
  documentation). This should fix #1597.
- This update adds the ability to add multiple functions to hooks
  without a list:

    (add-hook! 'some-mode-hook
               #'do-something
               #'do-something-else)

- The indentation logic has been changed so that consecutive function
  symbols at indented at the same level as the first argument, but forms
  are indent like a defun.

    (add-hook! 'some-mode-hook
               #'do-something
               #'do-something-else)

    (add-hook! 'some-mode-hook
      (message "Hello"))

modules/lang/emacs-lisp/config.el

@@ -47,24 +47,16 @@ This marks a foldable marker for `outline-minor-mode' in elisp buffers.")
   ;; variable-width indentation is superior in elisp
   (add-to-list 'doom-detect-indentation-excluded-modes 'emacs-lisp-mode nil #'eq)
 
-  ;; Special indentation behavior for `add-hook'; indent like a defun block if
-  ;; it contains `defun' forms and like normal otherwise.
-  (defun +emacs-lisp-indent-add-hook-fn (indent-point state)
-    (goto-char indent-point)
-    (when (looking-at-p "\\s-*(defun ")
-      (lisp-indent-defform state indent-point)))
-  (put 'add-hook 'lisp-indent-function #'+emacs-lisp-indent-add-hook-fn)
-
   ;; Use helpful instead of describe-* from `company'
   (advice-add #'elisp--company-doc-buffer :around #'doom-use-helpful-a)
 
   (add-hook! 'emacs-lisp-mode-hook
-    #'(outline-minor-mode
-       ;; fontificiation
-       rainbow-delimiters-mode
-       highlight-quoted-mode
-       ;; initialization
-       +emacs-lisp-extend-imenu-h))
+             #'outline-minor-mode
+             ;; fontificiation
+             #'rainbow-delimiters-mode
+             #'highlight-quoted-mode
+             ;; initialization
+             #'+emacs-lisp-extend-imenu-h)
 
   ;; Flycheck's two emacs-lisp checkers produce a *lot* of false positives in
   ;; emacs configs, so we disable `emacs-lisp-checkdoc' and reduce the