chore: add some github workflows

- Mitigate LuxDL/DocumenterVitepress.jl#81
- Keep the `gh-pages` branch small

.github/workflows/DeployDocs.yml

@@ -0,0 +1,58 @@
+# Sample workflow for building and deploying a Jekyll site to GitHub Pages
+name: Deploy GitHub Pages
+
+on:
+  # Runs on pushes targeting the default branch
+  push:
+    branches: [gh-pages]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
+# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  # Build job
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          ref: "gh-pages"
+          fetch-depth: 0 # Not needed if lastUpdated is not enabled
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+      - name: Fix Symlinks for Vitepress
+        run: |
+          find -type l -exec bash -c 'dir="$0"; newlnk=${dir:2}; lnk="$(readlink -m "$0")"; orglnk=$(basename $lnk); echo "$newlnk <--> $orglnk"; rm "$0"; cp -r $lnk "$0"; cd "$0"; grep "$orglnk" . -lr | xargs sed -i "s/$orglnk/$newlnk/g"; cd ..' {} \;
+          ls -al;
+      - name: Build with Jekyll
+        uses: actions/jekyll-build-pages@v1
+        with:
+          source: ./
+          destination: ./_site
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+
+  # Deployment job
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

.github/workflows/DocCleanUp.yml

@@ -0,0 +1,26 @@
+name: Doc Preview Cleanup
+
+on:
+  pull_request:
+    types: [closed]
+
+jobs:
+  doc-preview-cleanup:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout gh-pages branch
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+      - name: Delete preview and history + push changes
+        run: |
+            if [ -d "previews/PR$PRNUM" ]; then
+              git config user.name "thofma"
+              git config user.email "thofma@gmail.com"
+              git rm -rf "previews/PR$PRNUM"
+              git commit -m "delete preview"
+              git branch gh-pages-new $(echo "delete history" | git commit-tree HEAD^{tree})
+              git push --force origin gh-pages-new:gh-pages
+            fi
+        env:
+            PRNUM: ${{ github.event.number }}