Add comparison screenshots.

whatsnew.htm

@@ -55,7 +55,11 @@ For conditions of distribution and use, see <a href="https://jrsoftware.org/file
   <li>Setup wizard pages <a href="https://jrsoftware.org/images/is-welcome-org.png">Select Destination Location</a> and <a href="https://jrsoftware.org/images/is-finished-org.png">Setup Completed</a> at 100% DPI.</li>
   <li>Setup wizard pages <a href="https://jrsoftware.org/images/is-welcome-org-175.png">Select Destination Location</a> and <a href="https://jrsoftware.org/images/is-finished-org-175.png">Setup Completed</a> at 175% DPI.</li>
   <li>Compiler IDE themes <a href="https://jrsoftware.org/images/is-ide-org.png">Light</a> and <a href="https://jrsoftware.org/images/is-ide-dark-org.png">Dark</a> at 100% DPI.</li>
- </ul>
+</ul>
+<p>Comparison screenshots of the previous version:</p>
+<ul>
+  <li>Setup wizard pages <a href="https://jrsoftware.org/images/is-welcome-org-175-old.png">Select Destination Location</a> and <a href="https://jrsoftware.org/images/is-finished-org-175-old.png">Setup Completed</a> at 175% DPI in version 6.1.2.</li>
+</ul>
 <p><span class="head2">Other changes</span></p>
 <ul>
   <li>Links displayed by [Setup] section directives <tt>LicenseFile</tt>, <tt>InfoBeforeFile</tt> and <tt>InfoAfterFile</tt> are now executed as the original user if possible when clicked.</li>