ci(404): add copy 404.html into root folder for gh-pages

Author: Lemon73-Computing

.github/workflows/deploy.yml

@@ -69,6 +69,9 @@ jobs:
             --minify \
             --baseURL "${{ steps.pages.outputs.base_url }}/" \
             --cacheDir "${{ runner.temp }}/hugo_cache"
+      - name: Copy 404.html Page for GitHub Pages
+        run: |
+          cp public/en/404.html public/404.html
       - name: Cache Save
         id: cache-save
         uses: actions/cache/save@v4