Additional user settings

[emcniece]

There are some other interfaces that could benefit from having stored settings:

• Sidebar dropdown status
• Max terminal line count

It may be worth changing the localStorage settings to a more generic abstraction layer at this point. An HTML attribute like [data-setting] could bind a click/change/touch event to the element that would trigger save_settings and store all element data with this particular data attribute.

[emcniece]

Related: #51