fix: Added back extension item

en/manual/toc.yml

@@ -17,6 +17,8 @@ items:
     items:
       - name: Install Stride
         href: get-started/install-stride.md
+      - name: Visual Studio extension
+        href: get-started/visual-studio-extension.md
       - name: Update Stride
         href: get-started/update-stride.md
       - name: Launch Stride