Add hotswap for Kailh

[simoneruffini]

Modify Pcb to accomodate hotswappable kailh MX switch sockets, available here. Not to be confunsed with choc mount (the low profile version of kailh switches)

The footprint can be found here The type of footprint could be either one of:

• those: if the only way to use the pcb is to have the switches hotswappable.
• those: if the way to use the pcb is either via throughole soldering or via hotswap.

In either case, the choosen version shall be the one with only one central hole (less holes less cost). The reversible versions of the footprints are not neeeded if there will be a left module pcb and a right module pcb

[simoneruffini]

In the current pcb there are 2 types of footprint: 1) The ones with option for inner led and embedded led (column 7) 2) the ones with options for rectangular leds with distance pad of ~7mm

For this type of keyboard I don't want led's and in anyway they conflict with the hot-swappable keyswitch footprint. So those options will be removed.

If the leds are really a necessity, probably a good example to take a look at is this board