@DefaultValue doesn't follow JSON Schema standard

[DrewWeth]

The @DefaultValue annotation seems to add a description instead of actually adding a metadata field called default: true

https://json-schema.org/understanding-json-schema/reference/generic.html

Here's the test that doesn't abide by the standard

scala-schema/src/test/scala/fi/oph/scalaschema/JsonSchemaTest.scala

Line 104 in 0d6944e

jsonSchemaOf(classOf[BooleansWithDefault]) should equal("""{"type":"object","properties":{"field":{"type":"boolean","description":"(default value: true)"}},"id":"#booleanswithdefault","additionalProperties":false,"title":"Booleans with default"}""")