Add `decouple` processor to the default config

[nslaughter]

Is your feature request related to a problem? Please describe. Without the decouple processor in the pipeline there have been lengthy delays waiting on the Collector layer to flush telemetry. The README explains the situation.

Describe the solution you'd like Add decouple processor to the default pipeline config. This is just adopting a sensible default that's more likely to benefit the community as a whole and will not limit the opportunity of users who disagree with the approach to override for the present state.

Describe alternatives you've considered The current approach is to document for users how to override default config. This doesn't seem like the right approach given the significant benefit of using the decouple processor.

Additional context I don't currently have the comparison data accessible, however this has been the subject of some research in the community and I can add details for discussion.

[xThomo]

You linked the Makefile in the issue description, I think you meant this README

Any idea when #1197 will be merged? It looks like a simple change.

[nslaughter]

You linked the Makefile in the issue description, I think you meant this README

Any idea when #1197 will be merged? It looks like a simple change.

Thanks for the correction and the interest in #1197. What's happened here is an intervening idea where the decoupleprocessor could be added to the end of pipelines which contain a batch processor. I've written up the code for that in my fork and will be documenting it better before sharing for approval next week.

[nslaughter]

Addressed in #1255