R1:f79320e64e8f

Render default/current settings in the same format they'll be edited

Summary:
Fixes T4773. For config settings of type `list<string>`, `set`, or `list<regex>`, the "defaults" table and "examples" aren't always in the same format you should actually use when changing the setting.

This is pretty confusing. Instead, always show the settings in the desired format. For example, if the user should enter a newline-separated list, show them a newline separated list.

Test Plan:
- Grepped for `list<string>`…