[FR] Add Piezo Disk soldering guide to docs site

[pyr0ball]

Is your feature request related to a problem? Please describe. Since the beta kits were shipped using bare piezo disks, end-users will need to solder their own wires to it.

Describe the solution you'd like Need to add a guide on how to do this to the documentation site, either with images or a video.

Additional context Originally suggested by maxcom