Add workflow to react on missing or ignored templates

The workflow creates a comment on the issue or PR that has a missing or ignored template asking the author to use the template properly.

.github/workflows/template-label.yml

@@ -0,0 +1,61 @@
+name: Template label comment
+
+on:
+  issues:
+    types: [labeled]
+  pull_request:
+    types: [labeled]
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  comment_on_label:
+    name: Comment on labeled issue/PR
+    if: ${{ github.event.label.name == 'template-ignored' || github.event.label.name == 'template-missing' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Get PR template
+        if: ${{ github.event.pull_request && github.event.label.name == 'template-missing' }}
+        run: |
+          set -euo pipefail
+          {
+            echo 'PR_TEMPLATE<<EOF'
+            curl https://raw.githubusercontent.com/TeamNewPipe/NewPipe/refs/heads/dev/.github/PULL_REQUEST_TEMPLATE.md
+            echo EOF
+          } >> $GITHUB_ENV
+
+      - name: Post comment
+        uses: actions/github-script@v6
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const label = context.payload.label && context.payload.label.name;
+            if (!label) return;
+            const isPR = !!context.payload.pull_request;
+            const number = isPR ? context.payload.pull_request.number : context.payload.issue.number;
+
+            let body = '';
+            if (label === 'template-ignored') {
+              body = 'Please fill in the template completely or at least as much as possible. The team needs more detailed information.';
+            } else if (label === 'template-missing') {
+              const kind = isPR ? 'PR' : 'issue';
+              let template;
+              if (isPR) {
+                template = '<details><summary>Raw template</summary>\n```\n' + process.env.PR_TEMPLATE + '\n```\n</details>';
+              } else {
+                template = '[Bug report template](https://raw.githubusercontent.com/TeamNewPipe/NewPipe/refs/heads/dev/.github/ISSUE_TEMPLATE/bug_report.yml), [Feature request template](https://raw.githubusercontent.com/TeamNewPipe/NewPipe/refs/heads/dev/.github/ISSUE_TEMPLATE/feature_request.yml)';
+              }     
+              body = `Thank you for creating this ${kind}. Please edit your description and add the template with the information: ${template}`;
+            } else {
+              return;
+            }
+
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: number,
+              body
+            });
+