Feature request: Enable layer with modifiers active

[dxmh]

This is often requested on Discord by new users.

Similar to how pressing &mo NUMBER currently enables a number layer, this new behaviour would allow for pressing something like &mom LSHIFT NUMBER to activate shift and enable the number layer — with this key pressed, pressing &kp N1 (from the number layer) would output !.

Additionally, I understand users also wish to use this key as a standalone modifier (for example, having the ability to hold the key and click the mouse for a shift-click).

[caksoylar]

This is now possible with macros merged in so I assume it can be closed, see the example in the docs for an implementation.