Add temporary header notification for upgrade (#535)

docs/index.html

@@ -66,7 +66,8 @@
           hook.beforeEach(function(content) {
             // Invoked each time before parsing the Markdown file.
             // ...
-            return content + custommarkdown;
+            var custommarkdown = '!> Note that there was a breaking change introduced to guild repository scripts on 15th October. If you are coming from release before, please be sure to check out the [upgrade](upgrade.md) instructions\n'
+            return custommarkdown + '\n' + content;
           });
           //hook.doneEach(function() {
           //  // Invoked each time after the data is fully loaded, no arguments,