dumb-jump: bind key instead of enable mode

doc/DOCUMENTATION.org

@@ -1823,6 +1823,7 @@ The ~SPC j~ prefix is for jumping, joining and splitting.
 | ~SPC j J~   | jump to a suite of two characters in the buffer (works as an evil motion)         |
 | ~SPC j k~   | jump to next line and indent it using auto-indent rules                           |
 | ~SPC j l~   | jump to a line with avy (works as an evil motion)                                 |
+| ~SPC j q~   | show the dumb-jump quick look tooltip                                              |
 | ~SPC j u~   | jump to a URL in the current buffer                                               |
 | ~SPC j v~   | jump to the definition/declaration of an Emacs Lisp variable                      |
 | ~SPC j w~   | jump to a word in the current buffer (works as an evil motion)                    |

layers/+spacemacs/spacemacs-misc/packages.el

@@ -20,11 +20,15 @@
     :defer t
     :init
     (progn
+      ;; not activating `dumb-jump-mode' because it only adds key bindings, and
+      ;; they conflict with existing bindings (see
+      ;; https://github.com/syl20bnr/spacemacs/issues/7107)
+
+      (spacemacs/set-leader-keys "jq" #'dumb-jump-quick-look)
       ;; Since it's dumb, we add it to the end of the default jump handlers. At
       ;; the time of writing it is the only default jump handler. (gtags remains
       ;; mode-local)
-      (add-to-list 'spacemacs-default-jump-handlers 'dumb-jump-go 'append)
-      (add-hook 'prog-mode-hook 'dumb-jump-mode))))
+      (add-to-list 'spacemacs-default-jump-handlers 'dumb-jump-go 'append))))
 
 (defun spacemacs-misc/init-request ()
   (setq request-storage-directory