Update ecosystem.mdx

Add ast-finder, from the same authors as ast-builder

Author: danielo515

website/docs/ecosystem.mdx

@@ -17,6 +17,7 @@ The ecosystem is full of amazing resources and examples, please check them out.
 - [astexplorer.net](https://astexplorer.net/)
 - [recast](https://github.com/benjamn/recast)
 - [ast-builder](https://rajasegar.github.io/ast-builder/)
+- [ast-finder](https://rajasegar.github.io/ast-finder/)
 
 ## Blogs & Guides