Update README section JSON Schema Settings

[franzibrb]

Ahoi and thanks for this cool tool :)
I have noticed that the Readme.md might not be up-to-date.
This regards the section JSON Schema Settings:

` options.JsonSchemaGeneratorSettings.TypeNameGenerator = new DefaultTypeNameGenerator();

// Note: need to assign a new JsonSerializerSettings, not just set the properties within it.
options.JsonSchemaGeneratorSettings.SerializerSettings = new JsonSerializerSettings 
{
    ContractResolver = new DefaultContractResolver(),
    Formatting = Formatting.Indented;
};

`
JsonSchemaGeneratorSettings was renamed to SchemaOptions if i checked the code correctly.