implement config.yml

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Question or Suggestions
+    url: https://growi-slackin.weseek.co.jp/
+    about: If you have questions or suggestions, you can join our Slack team and talk about anything, anytime.