Instrumenting the Application with OpenTelemetry and Prometheus

Our application has already been set up with a logger, but we need traces and metrics to achieve observability. The OpenTelemetry project aims to support all three (logging, traces, and metrics) in the Go SDK, but in version v1.10, only tracing is stable. So, we will leave our logger in place and interact directly with Prometheus for our metrics. We will begin with OpenTelemetry and distributed tracing.