K250VS BSE Mods

Just some small modifications for the K250VS BSE edition.

I wanted to add some Hall-O endstop holders, magball carriages with a built-in 5mm diameter by 3mm deep magnet hole for Hall effect endstops, along with a mount for the RAMPS, and a generic electronics mount (which is a bit larger than it needs to be).

I was working on an SSR mount (for an AC heated bed), but instead decided to go with the stock 24v DC PSU and 24v DC Kapton heater to get my build started sooner.