mention deserialization too

Author: karenetheridge

src/oas.md

@@ -777,7 +777,7 @@ MUST NOT appear in the same operation (or in the operation's path-item) as an `i
 
 #### Fixed Fields
 
-The rules for serialization of the parameter are specified in one of two ways.
+The rules for serialization and deserialization of the parameter are specified in one of two ways.
 Parameter Objects MUST include either a `content` field or a `schema` field, but not both.
 See [Appendix B](#appendix-b-data-type-conversion) for a discussion of converting values of various types to string representations.