Update README.md (#356)

Author: spacether

README.md

@@ -95,7 +95,7 @@ And many more!
 - Openapi spec inline schemas supported at any depth in any location
 - Format support for: int32, int64, float, double, date, datetime, uuid
 - Payload values are not coerced when validated, so a datetime value can pass other validations that describe the payload only as type string
-- types are generated for enums of type string/integer/boolean using typing.Literal
+- types are generated for enums of type string/number/integer/boolean/null
 - String transmission of numbers supported with type: string, format: number
 - [Autogenerated thorough testing of json schema keyword features in models and endpoints](samples/client/3_0_3_unit_test/java/src/test/java/org/openapijsonschematools/client/components/schemas) which come from the [json schema test suite](https://github.com/json-schema-org/JSON-Schema-Test-Suite)
 - [Tests are passing in CI](https://app.circleci.com/pipelines/github/openapi-json-schema-tools/openapi-json-schema-generator?branch=master)