Clarify that a separate commit is useful

doc/null_safety/null_safe_migration.md

@@ -38,7 +38,8 @@ This codemod will:
 
 ### Codemod to run as part of a null safety migration
 
-Once you're ready to begin a null safety migration, run the `null_safety_migrator_companion` codemod:
+Once you're ready to begin a null safety migration, run the `null_safety_migrator_companion` codemod, and commit the
+hints it adds as a separate commit before proceeding with the rest of the migration. 
 
 ```bash
 dart pub global activate over_react_codemod
@@ -101,6 +102,9 @@ especially as it pertains to [prop nullability](#prop-nullability).
 
 ## Step 4: Run the migration tool
 
+> [!TIP]
+> **Be sure to commit any changes from step 3 prior to running the migrator tool!**
+
 Run the null safety migrator tool:
 
 - **For Workiva employees, use the [Workiva version of the migrator tool](https://github.com/Workiva/wnnbd?tab=readme-ov-file#migrating-a-package).**