[gnome-user-docs] Update how to change system keyboard shortcuts for 3.28

[Andre Klapper <aklapper src gnome org>]

commit 05dfa32809d077cb9e1a93fa707e9309e89fd9c1
Author: Andre Klapper <a9016009 gmx de>
Date:   Tue Sep 11 01:50:41 2018 +0200

    Update how to change system keyboard shortcuts for 3.28

 gnome-help/C/keyboard-shortcuts-set.page | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)
---
diff --git a/gnome-help/C/keyboard-shortcuts-set.page b/gnome-help/C/keyboard-shortcuts-set.page
index ad7cc6ec..0d35de50 100644
--- a/gnome-help/C/keyboard-shortcuts-set.page
+++ b/gnome-help/C/keyboard-shortcuts-set.page
@@ -66,16 +66,12 @@
       <p>Click on <gui>Keyboard</gui> to open the panel.</p>
     </item>
     <item>
-      <p>Select the <gui>Shortcuts</gui> tab.</p>
-    </item>
-    <item>
-      <p>Select a category in the left pane, and the row for the desired action
-      on the right. The current shortcut definition will change to
-      <gui>New accelerator…</gui></p>
+      <p>Under <gui>Keyboard Shortcuts</gui>, select a row for the desired
+      action in the right pane.</p>
     </item>
     <item>
       <p>Hold down the desired key combination, or press <key>Backspace</key> to
-      clear.</p>
+      reset, or press <key>Esc</key> to cancel.</p>
     </item>
   </steps>