Settings should include a custom field example

[DevinWalker]

User Story

As a developer, I need to know how to create a custom settings field through an example.

Details

Right now there's no example on adding a custom setting field and it's confusing to find out how to add one.

We should add two custom fields, one a practical field that we don't have in Core and another just an HTML output field for things like settings content / introductions.

Acceptance Criteria

• Two different custom settings fields are added as examples