Fix Opentelemetry docs

[llowinge]

Removed port 55680 as the default one is 4317 (based on https://github.com/open-telemetry/opentelemetry-collector/blob/main/receiver/otlpreceiver/README.md + open-telemetry/opentelemetry-python#1515).

Fixed insecure flag (explained in open-telemetry/opentelemetry-collector-contrib#5377).

Use fixed ports for jaegertracing container (easier to refer to those numbers).

[clahres]

I think there is a minor error in the docs:
The section receivers: [otlp,otlp/2] should be receivers: [otlp] in otel-collector-config.yaml. Should I open a new ticket?

[llowinge]

@clahres Great catch, i've prepared PR to fix it in #27219.