Update issue templates

Author: routerino

.github/ISSUE_TEMPLATE/bug_report.md

@@ -13,5 +13,8 @@ Provide the following:
 * Headscale Version:
 * Any Browser Errors (`control+shift+i` in chrome to see)
 
+** Note **
+No bug reports are currently being accepted against the alpha version of headscale. Test against the production/stable version.
+
 **Describe the bug**
 A clear and concise description of what the bug is. Screenshots if applicable