Change build command to docs:build in preview workflow

Author: santilland

.github/workflows/preview.yml

@@ -36,8 +36,8 @@ jobs:
       - if: github.event.action != 'closed'
         run: |
           npm install
-          npm run build -- --base /pr-preview/pr-${{ github.event.number }}/
+          npm run docs:build -- --base /pr-preview/pr-${{ github.event.number }}/
       - name: Deploy preview
         uses: rossjrw/pr-preview-action@v1
         with:
-          source-dir: .vitepress/dist/
+          source-dir: .vitepress/dist/