add GitHub workflows for testing build and updating tabi

.github/workflows/test-build.yml

@@ -0,0 +1,22 @@
+name: Test build
+
+on:
+  pull_request:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  test:
+    name: Test Site Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Zola Build
+        uses: shalzz/zola-deploy-action@v0.19.2
+        env:
+          BUILD_ONLY: true

.github/workflows/update-tabi.yml

@@ -0,0 +1,76 @@
+name: Update tabi theme
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "5 0 * * 1"  # Weekly on Mondays at 5 past midnight UTC
+
+jobs:
+  update-tabi:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+          fetch-depth: 0
+
+      - name: Configure Git
+        run: |
+          git config --global user.name "github-actions[bot]"
+          git config --global user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+      - name: Check for updates
+        id: check
+        run: |
+          cd themes/tabi
+          CURRENT=$(git rev-parse HEAD)
+          git fetch
+          git checkout origin/main
+          NEW=$(git rev-parse HEAD)
+          if [ "$CURRENT" != "$NEW" ]; then
+            # Get the changelog with links to commits and PRs
+            CHANGELOG=$(git log --pretty=format:"- %s [%h](https://github.com/welpo/tabi/commit/%H)" $CURRENT..$NEW | sed -E 's/#([0-9]+)/[#\1](https:\/\/github.com\/welpo\/tabi\/pull\/\1)/g')
+            echo "has_changes=true" >> "$GITHUB_OUTPUT"
+            echo "old_version=${CURRENT:0:7}" >> "$GITHUB_OUTPUT"
+            echo "new_version=${NEW:0:7}" >> "$GITHUB_OUTPUT"
+            echo "changelog<<EOF" >> "$GITHUB_OUTPUT"
+            echo "$CHANGELOG" >> "$GITHUB_OUTPUT"
+            echo "EOF" >> "$GITHUB_OUTPUT"
+          fi
+          cd ../..
+
+      - name: Create Pull Request
+        if: steps.check.outputs.has_changes == 'true'
+        run: |
+          BRANCH="update-tabi-$(date +%Y%m%d-%H%M%S)"
+          git checkout -b $BRANCH
+
+          git add themes/tabi
+          git commit -m "⬆️ Update tabi theme
+
+          From: ${{ steps.check.outputs.old_version }}
+          To: ${{ steps.check.outputs.new_version }}
+
+          Update tabi to the latest version from https://github.com/welpo/tabi"
+
+          git push origin $BRANCH
+          gh pr create \
+            --title "⬆️ Update tabi theme" \
+            --body "## Changes in this update
+
+            Updating \`themes/tabi\` from [\`${{ steps.check.outputs.old_version }}\`](https://github.com/welpo/tabi/commit/${{ steps.check.outputs.old_version }}) to [\`${{ steps.check.outputs.new_version }}\`](https://github.com/welpo/tabi/commit/${{ steps.check.outputs.new_version }})
+
+            ### Changelog
+            Submodule themes/tabi ${{ steps.check.outputs.old_version }}..${{ steps.check.outputs.new_version }}:
+            ${{ steps.check.outputs.changelog }}
+
+            ---
+
+            Auto-generated by the Update tabi theme workflow (in \`.github/workflows/update-tabi.yml\`)."
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}