Log4J appender open telemetry installation should be possible via log4j config

[faucct]

Is your feature request related to a problem? Please describe.

In some applications, for example Spark, it is not trivial to add arbitrary initialization code running on startup:
https://spark.apache.org/docs/3.5.1/configuration.html#configuring-logging
As this appender forces you to write Java code, this makes it hard to plug it into Spark, if not impossible:
https://github.com/open-telemetry/opentelemetry-java-instrumentation/tree/main/instrumentation/log4j/log4j-appender-2.17/library#usage

Describe the solution you'd like

I would like the OpenTelemetry installation to be possible via log4j configuration.
Here is an example of it from another plugin:
https://github.com/tkowalcz/tjahzi/tree/master/log4j2-appender

Describe alternatives you've considered

No response

Additional context

No response