Micro Switch Spacer for Central Vac Blast Gate

Adds an option for a micro switch for @juandavidbarrada's Central Vacuum Blast Gate.
https://www.thingiverse.com/thing:4297295

It uses a 20mm micro limit switch to turn the vacuum on similar to the one found here.
https://www.aliexpress.us/item/3256805737936037.html?spm=a2g0o.order_list.order_list_main.49.539b1802Lns5kq&gatewayAdapt=glo2usa