docs: update rstack org link (#1426)

Author: chenjiahan

website/docs/en/config/rsbuild/plugins.mdx

@@ -90,7 +90,7 @@ The following are common framework-agnostic plugins:
 - [TOML Plugin](https://github.com/rstackjs/rsbuild-plugin-toml): Import TOML files and convert them into JavaScript objects.
 
 :::tip
-You can find the source code of all official plugins in [web-infra-dev/rsbuild](https://github.com/web-infra-dev/rsbuild) and [rspack-contrib](https://github.com/rspack-contrib).
+You can find the source code of all official plugins in [web-infra-dev/rsbuild](https://github.com/web-infra-dev/rsbuild) and [rstackjs](https://github.com/rstackjs).
 :::
 
 ## Community plugins

website/docs/zh/config/rsbuild/plugins.mdx

@@ -90,7 +90,7 @@ export default defineConfig({
 - [TOML 插件](https://github.com/rstackjs/rsbuild-plugin-toml)：引用 TOML 文件，并将其转换为 JavaScript 对象。
 
 :::tip
-你可以在 [web-infra-dev/rsbuild](https://github.com/web-infra-dev/rsbuild) 和 [rspack-contrib](https://github.com/rspack-contrib) 中找到这些插件的源代码。
+你可以在 [web-infra-dev/rsbuild](https://github.com/web-infra-dev/rsbuild) 和 [rstackjs](https://github.com/rstackjs) 中找到这些插件的源代码。
 :::
 
 ## 社区插件