bpo-37039: IDLE - zoomheight fixes (GH-13576)

Move doc entry to match menu and refactor zoom function.
A followup patch will include a blurb.
diff --git a/Lib/idlelib/help.html b/Lib/idlelib/help.html
index bc287d6..228b319 100644
--- a/Lib/idlelib/help.html
+++ b/Lib/idlelib/help.html
@@ -313,14 +313,14 @@
 configuration dialog by selecting Preferences in the application
 menu. For more, see
 <a class="reference internal" href="#preferences"><span class="std std-ref">Setting preferences</span></a> under Help and preferences.</dd>
-<dt>Zoom/Restore Height</dt>
-<dd>Toggles the window between normal size and maximum height. The initial size
-defaults to 40 lines by 80 chars unless changed on the General tab of the
-Configure IDLE dialog.</dd>
 <dt>Show/Hide Code Context (Editor Window only)</dt>
 <dd>Open a pane at the top of the edit window which shows the block context
 of the code which has scrolled above the top of the window.  See
 <a class="reference internal" href="#code-context"><span class="std std-ref">Code Context</span></a> in the Editing and Navigation section below.</dd>
+<dt>Zoom/Restore Height</dt>
+<dd>Toggles the window between normal size and maximum height. The initial size
+defaults to 40 lines by 80 chars unless changed on the General tab of the
+Configure IDLE dialog.</dd>
 </dl>
 </div>
 <div class="section" id="window-menu-shell-and-editor">
@@ -943,7 +943,7 @@
 <br />
     <br />
 
-    Last updated on May 19, 2019.
+    Last updated on May 25, 2019.
     <a href="https://docs.python.org/3/bugs.html">Found a bug</a>?
     <br />