OpenTelemetry Erlang example

Steps to run the sample:

1. Start the app, otel-collector and Jaeger using docker compose.

docker-compose up

Once the they are running, Jaeger UI should be accessible at: http://localhost:16686/

And the erlang hello server at: http://localhost:8080/

2. Vizualise the traces:
   In the Jaeger UI, for every request you sent you will get a single trace with 2 spans like this one: