docs($theme-default): add version badge to smooth-scroll (close: #1930)(#1939)

Author: meteorlxy

packages/docs/docs/theme/default-theme-config.md

@@ -456,7 +456,7 @@ next: ./my-next-page # Will overwrite 'nextLinks' property from themeConfig
 ---
 ```
 
-## Smooth Scrolling
+## Smooth Scrolling <Badge text="1.2.0+" />
 
 The `themeConfig.smoothScroll` option allows you to enable smooth scrolling.
 

packages/docs/docs/zh/theme/default-theme-config.md

@@ -434,7 +434,7 @@ editLink: false
 ---
 ```
 
-## 页面滚动
+## 页面滚动 <Badge text="1.2.0+" />
 
 你可以通过 `themeConfig.smoothScroll` 选项来启用页面滚动效果。