Feat/update issue template (#3147)

Co-authored-by: Chenhe Gu <guchenhe@gmail.com>

.github/ISSUE_TEMPLATE/bug_report.yml

       label: Self Checks
       description: "To make sure we get to you in time, please check the following :)"
       options:
+        - label: This is only for bug report, if you would like to ask a quesion, please head to [Discussions](https://github.com/langgenius/dify/discussions/categories/general).
+          required: true
         - 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 submit this report (我已阅读并同意 [Language Policy](https://github.com/langgenius/dify/issues/1542)).

.github/ISSUE_TEMPLATE/config.yml

 blank_issues_enabled: false
 contact_links:
-  - name: "\U0001F4DA Dify user documentation"
-    url: https://docs.dify.ai/getting-started/readme
-    about: Documentation for users of Dify
-  - name: "\U0001F4DA Dify dev documentation"
-    url: https://docs.dify.ai/getting-started/install-self-hosted
-    about: Documentation for people interested in developing and contributing for Dify
+  - name: "\U0001F4E7 Discussions"
+    url: https://github.com/langgenius/dify/discussions/categories/general
+    about: General discussions and request help from the community

.github/ISSUE_TEMPLATE/help_wanted.yml

-name: "🤝 Help Wanted"
-description: "Request help from the community [please use English :）]"
-labels:
-  - help-wanted
-body:
-  - type: checkboxes
-    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 submit this report (我已阅读并同意 [Language Policy](https://github.com/langgenius/dify/issues/1542)).
-          required: true
-        - label: "Pleas do not modify this template :) and fill in all the required fields."
-          required: true
-  - type: textarea
-    attributes:
-      label: Provide a description of the help you need
-      placeholder: Briefly describe what you need help with.
-    validations:
-      required: true