docs: Add Shakapacker to Ecosystem (Ruby on Rails) (#13866)

* Add Shakapacker to Ecosystem (Ruby on Rails)

* Fix link formatting for Rspack Docs

* Update Shakapacker documentation for clarity

* Update link text for Rspack setup documentation

Author: cody-elhard

website/docs/en/guide/start/ecosystem.mdx

@@ -123,6 +123,13 @@ Rspack team and Nx team have collaborated to provide the [Rspack Nx plugin](http
 
 Re.Pack v5 uses Rspack and React Native community CLI's plugin system to allow you to bundle your application using Rspack and easily switch from Metro.
 
+### Shakapacker
+
+<Tag color="geekblue">Build tool</Tag>
+<Tag color="purple">Rails</Tag>
+
+[Shakapacker](https://shakapacker.com/) handles compiling rails frontend assets. See [Rspack setup Docs](https://github.com/shakacode/shakapacker/blob/main/docs/rspack.md)
+
 ### Storybook
 
 <Tag color="geekblue">UI development</Tag>