fix: issue templates not render correctly (#1763)

.github/ISSUE_TEMPLATE/bug_report.yml

 name: "🕷️ Bug report"
-description: Report errors or unexpected behavior [please use English :）]
+description: Report errors or unexpected behavior
 labels:
 - bug
 body:

.github/ISSUE_TEMPLATE/document_issue.yml

 name: "📚 Documentation Issue"
-description: Report issues in our documentation [please use English :）]
+description: Report issues in our documentation
 labels: 
 - ducumentation
 body:
   attributes:
     label: Self Checks
     description: "To make sure we get to you in time, please check the following :)"
+      - label: I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones.
+        required: true
       - label: I confirm that I am using English to file this report (我已阅读并同意 [Language Policy](https://github.com/langgenius/dify/issues/1542)).
         required: true
 - type: textarea

.github/ISSUE_TEMPLATE/feature_request.yml

 name: "⭐ Feature or enhancement request"
-description: Propose something new. [please use English :）]
+description: Propose something new.
 labels:
 - enhancement
 body:
   attributes:
     label: Self Checks
     description: "To make sure we get to you in time, please check the following :)"
+    options:
+      - label: I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones.
+        required: true
       - label: I confirm that I am using English to file this report (我已阅读并同意 [Language Policy](https://github.com/langgenius/dify/issues/1542)).
         required: true
 - type: textarea

.github/ISSUE_TEMPLATE/help_wanted.yml

     label: Self Checks
     description: "To make sure we get to you in time, please check the following :)"
     options:
+      - label: I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones.
+        required: true
       - label: I confirm that I am using English to file this report (我已阅读并同意 [Language Policy](https://github.com/langgenius/dify/issues/1542)).
         required: true
 - type: textarea