add upgrade notes

Author: niallzato

src/connections/sources/catalog/libraries/mobile/apple/migration.md

@@ -331,6 +331,9 @@ If you don't need to transform all of your Segment calls, and only want to trans
 
 ## 4. Upgrade Notes: Changes to the Configuration Object
 
+> info "You may need to call Identify as a one-off after migrating to Swift"
+> To preserve the userId for users identified prior to your migration to Swift, you must make a one-off Identify call. This is due to a storage format change between the Analytics-iOS and the Analytics-Swift libraries.
+
 The following option was renamed in Analytics-Swift:
 
 | Before                   | After                             |

src/connections/sources/catalog/libraries/mobile/kotlin-android/migration.md

@@ -386,7 +386,7 @@ If you don't need to transform all of your Segment calls, and only want to trans
 ## 4. Upgrade Notes
 
 > info "You might need to call Identify as a one-off after migrating to Kotlin"
-> To preserve the userId for users identified prior to your migration to Kotlin, you must make a one-off Identify call. This is due to a storage format change between the Analytics-Android and Analytics-Kotlin libraries.
+> To preserve the userId for users identified prior to your migration to Kotlin, you must make a one-off Identify call. This is due to a storage format change between the Analytics-Android and the Analytics-Kotlin libraries.
 
 ### 4.a) Changes to the Configuration Object