Add upgrading instructions to readme

kriskbx · kriskbx · commit dd906ad74ab4 · 2017-09-02T14:50:29.000+02:00
diff --git a/readme.md b/readme.md
@@ -63,6 +63,8 @@ token: 01234567891011
 
 ## updating
 
+**Updating from version <= 1.5? Please [click here](https://github.com/kriskbx/gitlab-time-tracker/blob/master/upgrade.md)!**
+
 Update gtt via yarn:
 
 ```shell
