added auto-build workflow files

.github/workflows/build-docusaurus.yml

@@ -0,0 +1,39 @@
+name: build-sveltekit
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Restore npm cache
+        uses: actions/cache@v4
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-npm-${{ hashFiles('package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-npm-
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build Docusaurus site
+        run: npm run build
+
+      - name: Save npm cache
+        if: ${{ github.ref_name == github.event.repository.default_branch }}
+        uses: actions/cache@v4
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-npm-${{ hashFiles('package-lock.json') }}