## Summary
Fixes: #155154 (introduced in #149878), builds on #155436 .
- Adds tests to ensure the configuration merging order, check those for
reference.
- Updates the README to explain the intention
For the tests, I needed to output something to the logs. I hope it's not
a big issue to log it. If needed, I might hide that behind a verbose- or
feature flag.
### Checklist
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
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Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
We are currently expecting serverless environments to be broken up into
several different envs, this config structure allows us to customize the
config based on that environment without major modifications to the
config loading system.
