Update tutorial to emit OTLP-formatted traces

[aisamu]

From https://www.jaegertracing.io/docs/1.6/client-libraries/#deprecating-jaeger-clients

Since v1.35, the Jaeger backend can receive trace data from the OpenTelemetry SDKs in their native OpenTelemetry Protocol (OTLP).

(Thanks for taking the time to write the tutorial!)

[steffan-westcott]

@aisamu Thank you for highlighting the migration of Jaeger to use OTLP. This is a good step forward for the OpenTelemetry community as it removes potential confusion for users.

I looked at your pull request and found it was missing some necessary configuration to make it work correctly. Briefly:

• The Jaeger Collector needs configuration option collector.otlp.enabled set to true to enable ingest of OTLP messages
• The default OTLP port 4317 on the Jaeger Collector needs to be available. This needs attention in examples (such as the tutorial) where an application running locally exports directly to a Jaeger instance running in a Docker container.

I have addressed these points for the tutorial and examples in this commit.

[aisamu]

Thanks for addressing those! I've tested it only with the all-in-one binary, which I suppose comes with all that preconfigured.