docs: add a note about yarn version support in Medusa Dev CLI guide (#5355)

www/apps/docs/content/development/fundamentals/local-development.md

@@ -43,6 +43,16 @@ yarn build
 
 Medusa provides a CLI tool to be used for development. This tool facilitates testing your local installment and changes to Medusa’s core without having to publish the changes to NPM.
 
+:::note
+
+The Medusa Dev CLI tool only works with yarn v1. You can use the following command to change the yarn version:
+
+```bash
+yarn set version classic
+```
+
+:::
+
 To install Medusa’s dev CLI tool:
 
 ```bash npm2yarn