typo

Author: raju-opti

MIGRATION.md

@@ -111,7 +111,7 @@ const optimizely = createInstance({
 });
 ```
 
-In case an invalid config is passed to `createInstance`, it returned `null` in v5. In v6, it will throw and error instead of returning null.
+In case an invalid config is passed to `createInstance`, it returned `null` in v5. In v6, it will throw an error instead of returning null.
 
 ## Project Configuration Management