Update docs/developing/migration.mdx

Co-authored-by: Copilot <[email protected]>

Author: Anmol1696

docs/developing/migration.mdx

@@ -38,7 +38,7 @@ Even though it's not recommended, if it's wanted to be kept off, please set expl
 
 ### BigInt
 
-The default value of `prototypes.typingsFormat.num64` has been changed into 'bigint' for bettern handling int64 fields.
+The default value of `prototypes.typingsFormat.num64` has been changed into 'bigint' for better handling int64 fields.
 
 If it's wanted to be kept to be 'long', please set explicitly: