Enhancement for Compact JSON

The current implementation seems to yield a pretty printed output of the ECS JSON. Would it be possible to optionally configure the layout to output compact JSON?

Perhaps it would be valuable to add analogous features with the same capability and intent as those related to the "compact", "eventEol" and "endOfLine" etc settings which are available on the OEM JSONLayout.

See https://logging.apache.org/log4j/2.x/manual/layouts.html where pretty print vs compact format is discussed.