Fix "h" in grep mode

By default this is bound to describe-mode, which is easily accessible
through other means.

Signed-off-by: Rudi Grinberg <rudi.grinberg@gmail.com>

evil-collection-grep.el

@@ -36,6 +36,7 @@
 (defun evil-collection-grep-setup ()
   "Set up `evil' bindings for `grep'."
   (evil-collection-define-key 'normal 'grep-mode-map
+    "h" #'evil-backward-char
     "n" 'evil-search-next
     "\C-j" 'next-error-no-select
     "\C-k" 'previous-error-no-select))