chore: improve url in issue template

Author: gyoshev

.github/ISSUE_TEMPLATE.md

@@ -6,7 +6,7 @@
 ## This repository is about to be archived, and its code is outdated.
 ##
 ## Log issues for Kendo UI Themes in the new monorepository:
-## https://github.com/telerik/kendo-themes
+## https://github.com/telerik/kendo-themes/issues/new
 ##
 ##
 ########################################################################