Add measures to reduce duplicate issues

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -71,3 +71,50 @@ body:
     attributes:
       label: Additional Context
       description: Anything else to add?
+  - type: checkboxes
+    attributes:
+      label: Confirmation
+      description: Please confirm the following before submitting your issue.
+      options:
+        - label: I have searched for existing issues
+          required: true
+  - type: checkboxes
+    attributes:
+      label: Confirmation
+      description: Please confirm the following before submitting your issue.
+      options:
+        - label: I have searched for existing issues
+          required: true
+  - type: textarea
+    attributes:
+      label: Environment
+      description: Provide details about your environment, such as operating system, browser, and version.
+      placeholder: |-
+        - Operating System: [Windows, macOS, Linux]
+        - Browser and Version: [Chrome, Edge, Firefox]
+  - type: textarea
+    attributes:
+      label: Expected Behavior
+      description: Describe what you expected to happen.
+      placeholder: I expected ...
+  - type: textarea
+    attributes:
+      label: Actual Behavior
+      description: Describe what actually happened.
+      placeholder: Instead, I saw ...
+  - type: textarea
+    attributes:
+      label: Additional Information
+      description: Provide any additional information that may help us understand the issue.
+      placeholder: Any other relevant information...
+  - type: checkboxes
+    attributes:
+      label: Confirmation
+      description: Please confirm the following before submitting your issue.
+      options:
+        - label: I have searched for existing issues
+          required: true
+        - label: I have checked the [Live Editor - Develop](https://develop.git.mermaid.live) to see if the issue is already fixed
+          required: true
+        - label: I have provided detailed information about the issue
+          required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -18,3 +18,6 @@ contact_links:
   - name: Live Editor - Next
     url: https://next.git.mermaid.live
     about: Try unreleased changes in the next branch.
+  - name: Search Existing Issues
+    url: https://github.com/mermaid-js/mermaid/issues
+    about: Please search through existing issues before creating a new one.

.github/ISSUE_TEMPLATE/diagram_proposal.yml

@@ -58,3 +58,10 @@ body:
       options:
         - I will try and implement it myself.
         - This is a proposal which I'd love to see built into mermaid by the wonderful community.
+  - type: checkboxes
+    attributes:
+      label: Confirmation
+      description: Please confirm the following before submitting your issue.
+      options:
+        - label: I have searched for existing issues
+          required: true

.github/ISSUE_TEMPLATE/syntax_proposal.yml

@@ -32,3 +32,21 @@ body:
     attributes:
       label: Screenshots
       description: If applicable, add screenshots to show possible examples of how the theme may look like.
+  - type: textarea
+    attributes:
+      label: Use Cases
+      description: If applicable, give some use cases for where this syntax would be useful.
+      placeholder: The Syntax could be used for ...
+  - type: textarea
+    attributes:
+      label: Syntax
+      description: |-
+        If possible, include a syntax which could be used to write the diagram.
+        Try to add one or two examples of valid use-cases here.
+  - type: checkboxes
+    attributes:
+      label: Confirmation
+      description: Please confirm the following before submitting your issue.
+      options:
+        - label: I have searched for existing issues
+          required: true

.github/ISSUE_TEMPLATE/theme_proposal.yml

@@ -40,3 +40,20 @@ body:
     attributes:
       label: Screenshots
       description: If applicable, add screenshots to show possible examples of how the theme may look like.
+  - type: textarea
+    attributes:
+      label: Use Cases
+      description: If applicable, give some use cases for where this theme would be useful.
+      placeholder: The theme could be used for ...
+  - type: textarea
+    attributes:
+      label: Additional Information
+      description: Provide any additional information that may help us understand the theme proposal.
+      placeholder: Any other relevant information...
+  - type: checkboxes
+    attributes:
+      label: Confirmation
+      description: Please confirm the following before submitting your issue.
+      options:
+        - label: I have searched for existing issues
+          required: true

.github/stale.yml

@@ -1,19 +1,19 @@
-# Number of days of inactivity before an issue becomes stale
-daysUntilStale: 60
-# Number of days of inactivity before a stale issue is closed
-daysUntilClose: 14
-# Issues with these labels will never be considered stale
-exemptLabels:
-  - Retained
-# Label to use when marking an issue as stale
-staleLabel: Inactive
-# Comment to post when marking an issue as stale. Set to `false` to disable
-markComment: >
-  This issue has been automatically marked as stale because it has not had
-  recent activity. It will be closed if no further activity occurs. Thank you
-  for your contributions.
-  If you are still interested in this issue and it is still relevant you can comment to revive it.
-# Comment to post when closing a stale issue. Set to `false` to disable
-closeComment: >
-  This issue has been been automatically closed due to a lack of activity. 
-  This is done to maintain a clean list of issues that the community is interested in developing.
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 30
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 7
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - Retained
+# Label to use when marking an issue as stale
+staleLabel: Inactive
+# Comment to post when marking an issue as stale. Set to `false` to disable
+markComment: >
+  This issue has been automatically marked as stale because it has not had
+  recent activity. It will be closed if no further activity occurs. Thank you
+  for your contributions.
+  If you are still interested in this issue and it is still relevant you can comment to revive it.
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: >
+  This issue has been been automatically closed due to a lack of activity. 
+  This is done to maintain a clean list of issues that the community is interested in developing.

.github/workflows/issue-triage.yml

@@ -18,3 +18,23 @@ jobs:
         with:
           repo-token: '${{ secrets.GITHUB_TOKEN }}'
           add-labels: 'Status: Triage'
+      - name: Check for duplicate issues
+        uses: actions/github-script@v3
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const { data: issues } = await github.issues.listForRepo({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              state: 'open',
+              labels: 'Status: Triage'
+            });
+            const duplicate = issues.find(issue => issue.title === context.payload.issue.title);
+            if (duplicate) {
+              await github.issues.addLabels({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.payload.issue.number,
+                labels: ['duplicate']
+              });
+            }