Example about loading pre-transpiled PMML service provider JAR files

[vruusmann]

See jpmml/jpmml-evaluator#257

The README file provides a TL;DR example that deals with in-memory transpilation.

However, in-memory transpilation is not a very common usage scenario. A much more relevant TL;DR example would be one, where PMML XML file is pre-emptively transpiled into a PMML service provider JAR file, and then loaded in a different time/place into an org.jpmml.evaluator.Evaluator instance.