Fixed a spelling typo

Author: DRSDavidSoft

index.html

@@ -75,7 +75,7 @@ <h3>Download</h3>
                     <a id="mini" onclick="_gaq.push(['_trackEvent', 'Download', 'mini'])" href="https://github.com/cmderdev/cmder/releases/latest">
                         <button class="gray">Download Mini</button>
                     </a>
-                    <small is="mini-size">~7.8MB</small>
+                    <small id="mini-size">~7.8MB</small>
                 </div>
                 <div class="bit-2">
                     <a id="full" onclick="_gaq.push(['_trackEvent', 'Download', 'full'])" href="https://github.com/cmderdev/cmder/releases/latest">