Add new emacs-lisp :documentation lookup handler

Made to do-what-I-mean. Uses describe-symbol/helpful-symbol and falls
back to apropos.

modules/lang/emacs-lisp/autoload.el

@@ -122,3 +122,12 @@ library/userland functions"
                           if (file-in-directory-p buffer-file-name dir)
                           return t)))
     (flycheck-mode -1)))
+
+;;;###autoload
+(defun +emacs-lisp-lookup-documentation (thing)
+  "Lookup THING with `helpful-symbol' if it's a symbol, apropos otherwise."
+  (cond ((not thing)
+         (call-interactively #'helpful-symbol))
+        ((if-let* ((sym (intern-soft thing))) (helpful-symbol sym)))
+        ((apropos (format "^%s" thing)))
+        ((apropos thing))))

modules/lang/emacs-lisp/config.el

@@ -18,7 +18,7 @@
   (set-eval-handler! 'emacs-lisp-mode #'+emacs-lisp-eval)
   (set-lookup-handlers! 'emacs-lisp-mode
     :definition    #'elisp-def
-    :documentation #'info-lookup-symbol)
+    :documentation #'+emacs-lisp-lookup-documentation)
   (set-docsets! 'emacs-lisp-mode "Emacs Lisp")
   (set-pretty-symbols! 'emacs-lisp-mode :lambda "lambda")
   (set-rotate-patterns! 'emacs-lisp-mode