update Make changes section of readme

Author: Jarvis Luong

README.md

@@ -18,8 +18,8 @@ Want to help improve the documentation? That would be so very much appreciated.
 
 ### Make changes
 
-- The `docs` directory contains the markdown files used to generate the website. Change them and refresh the page when running the documentation locally and you will see the changes reflected.
-- If you want to add a new page, you need to add it to [sidebars.json](https://github.com/react-navigation/react-navigation.github.io/blob/source/sidebars.json) and then restart the server.
+- Each documentation version of `react-navigation` is generated by the markdown files located in `versioned_docs`. Change them and refresh the page when running the documentation locally and you will see the changes reflected.
+- If you want to add a new page, you need to add it to the corresponding [sidebars.json file](https://github.com/https://github.com/react-navigation/react-navigation.github.io/tree/source/versioned_sidebars) and then restart the server.
 
 ## Things you need to be a collaborator to do