Fixed a small type (#1921)

This is a very little nitpick, but I hope it is useful anyway.

Author: sharkwouter

docs/migration-from-swagger-codegen.md

@@ -184,7 +184,7 @@ Example: `org.openapitools.codegen.DefaultGenerator`
 
 ### Body parameter name
 
-In OpenAPI spec v3, there's no body parameter, which is replaced by [Request Body Object](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.1.md#request-body-object). The parameter name for Request Body is named automatically based on the model name (e.g. User). To control how the "Request Body" parmaeter is named, please add the vendor extension `x-codegen-request-body-name` to the operation:
+In OpenAPI spec v3, there's no body parameter, which is replaced by [Request Body Object](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.1.md#request-body-object). The parameter name for Request Body is named automatically based on the model name (e.g. User). To control how the "Request Body" parameter is named, please add the vendor extension `x-codegen-request-body-name` to the operation:
 
 OpenAPI Spec v3:
 ```yaml