Improve readme to make it more clear about how PRs work

README.md

@@ -10,3 +10,11 @@ Once you have passed these tests your app will be published to the public repo a
 People will then be able to download your app and receive updates.
 
 You will have to submit a Pull Request for every update, We will still check the app but it won't be as thorough as the first time.
+
+## How do I make a good Pull Request?
+
+You will need to meet the following requirements to have a good PR:
+
+- It includes a change that will add/update your app(s)
+- It does not modify or remove any other apps' code
+- Run `listing.js` in a Node.js environment locally after adding your app to ensure the listings are updated