Tidy up already-on-app-stores fyi (#170)

* docs: tidy up `already-on-app-stores` fyi

* Apply suggestions from code review

---------

Co-authored-by: Aman Mittal <[email protected]>

already-on-app-stores.md

@@ -1,14 +1,26 @@
-If you have a new version of your app that you've built with Expo tools and you'd like to replace your existing app on the app stores with it, how do you do that? It's actually pretty straightforward.
+# Replacing your existing app on the app stores
+
+If you have a new version of your app built with Expo tools and you'd like to replace your existing app on the app stores with it, here's a simple guide to help you through the process.
 
 ## iOS
 
-- Configure your Expo app to use the same [bundle identifier](https://docs.expo.dev/versions/latest/config/app/#bundleidentifier) on iOS as your existing App Store listing.
-- If you're using EAS Build, then you can build and let automatic credential management use the rest. If you're not, then you can reuse whatever your previous deployment process was.
+1. **Configure bundle identifier:**
+
+   - Ensure your Expo app uses the same [bundle identifier](https://docs.expo.dev/versions/latest/config/app/#bundleidentifier) as your existing App Store listing.
+
+2. **Build and deployment:**
+
+   - If you're using EAS Build, then you can build and let automatic credential management use the rest. If you're not, then you can reuse whatever your previous deployment process was.
 
 ## Android
 
-- Configure your Expo app to use the application identifier (called ["package" in app.json](https://docs.expo.dev/versions/latest/config/app/#package)) on Android as your existing Play Store listing.
-- Ensure that you sign your Android app using your existing keystore. If you're using EAS Build, you can learn more about how to do that in the ["Using existing credentials" guide](https://docs.expo.dev/app-signing/existing-credentials/).
+1. **Configure application identifier:**
+
+   - Ensure your Expo app uses the same application identifier ([`package` in app config](https://docs.expo.dev/versions/latest/config/app/#package)) as your existing Play Store listing.
+
+2. **Signing the app using existing keystore:**
+
+   - Ensure that you sign your Android app using your existing keystore. If you're using EAS Build, you can learn more about how to do that in the ["Use existing credentials" guide](https://docs.expo.dev/app-signing/existing-credentials/).
 
 ## Other considerations