Use lychee to test links

Author: lyashevska

template/.github/workflows/{% if AddLinkCheck %}link-check.yml{% endif %}

@@ -0,0 +1,33 @@
+name: link-check
+
+on:
+  push:
+    branches:
+    - main
+  pull_request:
+    branches:
+    - main
+  schedule:
+    - cron: '0 0 * * 0' # every Sunday at 00:00
+
+jobs:
+  linkChecker:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Link Checker
+        id: lychee
+        uses: lycheeverse/lychee-action@v1
+        with:
+          # fail action if there are broken links
+          fail: true
+
+      - name: Create Issue From File
+        # create issues only when triggered by schedule
+        if: github.event_name == 'schedule' && env.lychee_exit_code != 0
+        uses: peter-evans/create-issue-from-file@v5
+        with:
+          title: Link Checker Report
+          content-filepath: ./lychee/out.md
+          labels: report, automated issue