Update website/docs/en/config/lib/id.mdx

Co-authored-by: Timeless0911 <[email protected]>

Author: fi3ework

website/docs/en/config/lib/id.mdx

@@ -11,7 +11,7 @@ Rslib uses Rsbuild's [environments](https://rsbuild.dev/guide/advanced/environme
 
 :::
 
-## The default ID
+## Default Value
 
 By default, Rslib automatically generates an ID for each library in the format `${format}${index}`. Here, `format` refers to the value specified in the current lib's [format](/config/lib/format), and `index` indicates the order of the library within all libraries of the same format. If there is only one library with the current format, the `index` will be empty. Otherwise, it will start from `0` and increment.