chore: import upstream snapshot with attribution

.github/workflows/links.yml

@@ -0,0 +1,35 @@
+name: GitHub Markdown Links
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: "0 8 * * 6"
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - run: sudo apt-get update -y
+      - run: >-
+          sudo apt-get install -y
+          pandoc
+      - uses: actions/checkout@v6
+      - run: |
+          find . -name '*.html' -delete
+      - run: |
+          find . -name '*.md' -exec pandoc -i {} -o {}.html \;
+      - uses: anishathalye/proof-html@v2
+        with:
+          directory: .
+          check_html: false
+          check_favicon: false
+          ignore_missing_alt: true
+          tokens: |
+            {"https://github.com": "${{ secrets.GITHUB_TOKEN }}"}
+          ignore_url: |
+            https://jair.org/index.php/jair/article/view/12125
+            https://stackoverflow.com/questions/41573587/what-is-the-difference-between-venv-pyvenv-pyenv-virtualenv-virtualenvwrappe
+          ignore_url_re: |
+            https://www.gnu.org/software/wget
+          swap_urls: |
+            {"^(\\..*)\\.md(#?.*)$": "\\1.md.html\\2",
+             "^(https://github\\.com/.*)#.*$": "\\1"}