Update issue templates

Author: hoothin

.github/ISSUE_TEMPLATE/custom-rule-request.md

@@ -1,6 +1,8 @@
 ---
 name: Custom rule request
-about: Seek help for custom rule
+about: Seek help for custom rule. Please publish the issue according to the guidelines,
+  otherwise the request will be ignored and closed directly. Your understanding and
+  cooperation are appreciated.
 title: ''
 labels: ''
 assignees: ''

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,6 +1,8 @@
 ---
 name: Feature request
-about: Suggest an idea for this project
+about: Suggest an idea for this project. Please publish the issue according to the
+  guidelines, otherwise the request will be ignored and closed directly. Your understanding
+  and cooperation are appreciated.
 title: ''
 labels: ''
 assignees: ''