[Feature Request] Support for Combos

[pawelkontek]

Description

Support Combos https://docs.qmk.fm/#/feature_combo?id=combos

The first version could just add additional, small keys between the keys in the UI, like this:

This could be toggled on and off in the UI

[seabadger]

Another way to represent combos (used by ZSA's Oryx, the configurator for ErgoDox, Moonlander, and Planck keyboards),
is to display a list of combos defined for the current layer (each combo is assigned a descriptive name that shows up in the list). When a combo is selected from the link, the keys that are part of the combo are visually highlighted.