Feature Request: Consider a tap vs hold option

[Vashinator]

This isn't as big of a deal to me as #83
But it would be a nice feature to be able to have a tap vs held option when configuring a key.

Some ideas I've seen:

• having caps when a letter is held down (though that may be a keyboard wide setting).
• Doing more with caps lock by using the tap to be standard caps lock and hold to be a combo of modifier keys.
• Using the Fn key, a tap switches the layer until it's tapped again, a hold only has the layer active while it's being held.

[leviport]

Duplicate of pop-os/keyboard-configurator#64

Since Launch uses QMK firmware, this is already supported, but firmware must be manually customized and flashed, rather than mapped using the Configurator. Support for more advanced functionality, including mod-tap is currently being worked on.