This commit removes the old jaegerTracing section from the values.yaml file. Indeed, OpenTracing support has been replaced in 0.46.0 with OpenTelemetry support, and properties like quarkus.jaeger.service.name are not honored anymore.

Instead, this commit creates a new tracing section that maps to OpenTelemetry configuration properties.

This commit also introduces some doc changes:

- In helm/nessie/README.md to explain how to test Nessie with OpenTelemetry enabled, and with custom Docker images;
- In site/docs/try/configuration.md to create a new Traces chapter with a few troubleshooting tips.