Fix deriving typo

Author: Kevan Stannard

misc_docs/syntax/decorator_deriving.mdx

@@ -8,7 +8,7 @@ category: "decorators"
 
 When the `@deriving` decorator is applied to a **record** type,
 it expands the type into a factory function plus a set of
-getter/setter functions for it's fields.   
+getter/setter functions for its fields.   
 
 > Note that this is an outdated decorator and you may no longer need to use it.
 > See [Convert Record Type to Abstract Record](/docs/manual/latest/generate-converters-accessors#convert-record-type-to-abstract-record) for more details.