Merge pull request nus-cs2103-AY2021S1#78 from royleochan/branch-Update-Help

Update help url

Author: jerrylchong

src/main/java/seedu/address/ui/HelpWindow.java

@@ -15,7 +15,7 @@
  */
 public class HelpWindow extends UiPart<Stage> {
 
-    public static final String USERGUIDE_URL = "https://se-education.org/addressbook-level3/UserGuide.html";
+    public static final String USERGUIDE_URL = "https://ay2021s1-cs2103-f10-2.github.io/tp/UserGuide.html";
     public static final String HELP_MESSAGE = "Refer to the user guide: " + USERGUIDE_URL;
 
     private static final Logger logger = LogsCenter.getLogger(HelpWindow.class);