Add a quick guide for the Otel integration

[manast]

We should have a new section in our documentation "Telemetry" with some overview of telemetry, but specifically add a subsection OpenTelemetry with a quick guide for starting using it as fast and quickly as possible. This is not to be confused with a more complete tutorial where a example repo is also provided for a complete use-case of using open-telemetry in a larger project.