Feature request: printing metrics

[fubhy]

I find myself in situations where I'd like to conveniently access and print metrics in the browser console or terminal when running a program.

I think it would be great if @effect/io exposed a generic pretty printer for metrics that could be used standalone.

Tim is currently working on a metrics module for otel: https://github.com/Effect-TS/opentelemetry/pull/9 that could be used as inspiration.