Change result table "open and quit" shortcut to use Ctrl+Alt+Shift to avoid conflict with "jump to row". Add "copy text and quit"

src/doc/user/usermanual.html

@@ -428,7 +428,7 @@ alink="#0000FF">
     <div class="list-of-tables">
       <p><b>List of Tables</b></p>
       <dl>
-        <dt>3.1. <a href="#idm1472">Keyboard shortcuts</a></dt>
+        <dt>3.1. <a href="#idm1478">Keyboard shortcuts</a></dt>
       </dl>
     </div>
     <div class="chapter">
@@ -4074,8 +4074,16 @@ fs.inotify.max_user_watches=32768
           the GUI preferences. Most shortcuts are specific to a
           given context (e.g. within a preview window, within the
           result table).</p>
+          <p>Most shortcuts can be changed to a preferred value by
+          using the GUI shortcut editor: <span class=
+          "guimenu">Preferences</span> → <span class=
+          "guimenuitem">GUI configuration</span> → <span class=
+          "guimenuitem">Shortcuts</span>. In order to change a
+          shortcut, just click the corresponding cell in the
+          <span class="guilabel">Shortcut</span> column, and type
+          the desired sequence.</p>
           <div class="table">
-            <a name="idm1472" id="idm1472"></a>
+            <a name="idm1478" id="idm1478"></a>
             <p class="title"><b>Table&nbsp;3.1.&nbsp;Keyboard
             shortcuts</b></p>
             <div class="table-contents">