Support for Opentelemetry

[fdocr]

This is a very minimalistic project. Pluggable (optional) tools could be integrated, like Datadog, Honeycomb.io, Honeybadger, etc

Given that this is a Sinatra app and I'm not very experienced in the best practices to start modularizing (extracting things from the one server.rb in a organized fashion) I'm opening this issue with the discussion label.

Any thoughts/recommendations are welcome. Once a path forward has been agreed would be the best time to send in a PR (contributions welcome at this time).

Note: #3 is only an experiment. The app is intended to work as a Sinatra app for simplicity at the moment.

[fdocr]

Now decided to integrate jgaskins/opentelemetry shard. A working example can be found here.