Example code on README.md please plus links to examples in src

[davidmoten]

I wasted a number of minutes looking for the simplest example on the README.md and in the wiki but didn't find one. Please put a simple example on the README.md like:

JsonSchemaFactory factory = JsonSchemaFactory.byDefault();
ObjectMapper m = new ObjectMapper();
JsonSchema jsonSchema = factory
        .getJsonSchema(m.readTree(schemaFile));
JsonNode json = m.readTree(jsonFile);
ProcessingReport report = jsonSchema.validate(json);
System.out.println(report);

Plus please put links to the src examples.

Thanks for the very useful library!