PLease update doc about schema resolution

[chernyh]

https://github.com/everit-org/json-schema#ref-resolution

No need/possibility to set ClassPathAwareClient, one can just use

SchemaLoader.load(jsonSchema, new ClassPathAwareSchemaClient());

where client is
public class ClassPathAwareSchemaClient implements SchemaClient {

@Override
public InputStream get(final String url) {
    return ClassPathAwareSchemaClient.class.getResourceAsStream(url);
}

}

thanks!