Update src/fragments/lib/push-notifications/react-native/migrate_from_previous_version/migrate-from-previous-version.mdx

Co-authored-by: Jim Blanchard <[email protected]>

Author: cshfang

src/fragments/lib/push-notifications/react-native/migrate_from_previous_version/migrate-from-previous-version.mdx

@@ -39,7 +39,7 @@ Amplify Push Notifications now requires a minimum target of iOS 13.0.
 
 1. Open `Podfile` located inside the `/ios` folder of your React Native project with a text editor.
 
-2. Update `platform :ios` to at least `13.0`
+2. Update `platform :ios` to at least `13.0`.
 
 ```ruby
 platform :ios, '13.0'