metric expose with type

[SjhZju]

hi, I found that the metrics's metricType exposed can not be recognized clearly (gauge, counter, histogram etc.) Would you like to add its description so that we can define how to query it.

[francisoliverlee]

@SjhZju a little change on file: RMQMetricsServiceImpl.java change a method to this below public void metrics(StringWriter writer) throws IOException { TextFormat.write004(writer, registry.metricFamilySamples()); }