ci: add caching for Docusaurus build

Author: wellwelwel

.github/workflows/cd_deploy.yml

@@ -37,6 +37,15 @@ jobs:
       - name: Checking Lint
         run: npm run lint
 
+      - name: Cache Docusaurus
+        uses: actions/cache@v5
+        with:
+          path: |
+            .docusaurus
+            node_modules/.cache
+          key: docusaurus-${{ hashFiles('docusaurus.config.ts', 'package-lock.json') }}
+          restore-keys: docusaurus-
+
       - name: Building Site
         run: npm run build