## Summary of the Pull Request
_This is attempt 2 at this feature_. The original PR can be found at #3369.
These are settings that apply to _every_ profile, before user customizations.
If the user wants to add "default profile settings", they can make the `"profiles"` property an _object_, instead of a list, and add `"defaults"` key underneath that object. The users list of profiles should then be under the `list` property of the `profiles` object.
## References
#2515, #2603, #3369, #3569
## PR Checklist
* [x] Closes#2325
* [x] I work here
* [x] Tests added/passed
* [x] schema, docs updated
## Detailed Description of the Pull Request / Additional comments
~~Discussion in #2325 itself serves as the "spec" for this task. I thought we'd need more discussion on the topic, but it ended up being pretty straightforward.~~
I should not have said that in the original PR. We've had a better spec review now that I think we're happier with.
## Validation Steps Performed
_ran the tests_
3ccc999e1f