Change order of parameter evaluation

[RedX2501]

Currently the parameters are evaluated in the order docs

Command line args are loaded first, then config file, then environment variables.

I would suggest to invert it.

First Environment, then config and finally command line args as this makes overriding the values easier and supports understandability.

Example:

In your .bashrc you have:

export OTEL_EXPORTER_OTLP_TIMEOUT=72h

and when calling you use:

otel-cli span background --timeout 1s &

It is surprising now that it blocks for a long time. To actually have the timeout be 1s you must:

OTEL_EXPORTER_OTLP_TIMEOUT= otel-cli span background --timeout 1s &

and this becomes actually impossible if it is set in the config file as you would need to edit the file.