Organize keys better to make them easier to find

They keys in the Quantum-tab are somewhat sorted, but very hard to find. A simple Headline for each section (mod, hold tab mods, etc) would be really helpful already.

These headlines could also have a small explanation what these keys do. For beginners to see and understand the difference between mod(kc) and mod_t(kc) is not so easy, for example. Although the tooltips help already quite a bit.