Always show scroll bar

[Demiu]

Description of the new feature/enhancement

An ability to have the scroll bar always visible. Right now this is technically possible via the ease of use settings in windows, but that is a system-wide setting. It would be preferable to have a settings in the terminal so this config doesn't spill to every other program.

Proposed technical implementation details (optional)

A toggle in the appearance settings that will cause the scroll bar to be always shown