feat(navbar): toggle theme inside navbar (#759)

* feat(theme-toggle): toggle inside navbar

* chore: used partial parameters

* chore: create a constant for icons height inside navbar

* feat: better style integration

* review: invert enable label option

* review: change class value

* review

Co-authored-by: Xin <5097752+imfing@users.noreply.github.com>

* docs: theme toggle

* docs: translations

---------

Co-authored-by: Xin <5097752+imfing@users.noreply.github.com>

exampleSite/content/docs/guide/configuration.zh-cn.md

@@ -64,6 +64,12 @@ menu:
      params:
        icon: github
    ```
+5. 主题切换
+   ```yaml
+    - name: Theme Toggle
+      params:
+        type: theme-toggle
+   ```
 
 通过设置 `weight` 参数可以调整菜单项的排序。