Keystone Jack punch-down holder

This is a holder for a keystone jack to be safer when punching down RJ-45 wires. I remixed the stand because it wasn't _quite_ big enough to fit the [keystone jacks](https://smile.amazon.com/gp/product/B01FHBZF7E/) that I got.

I also added a hole through the bottom to make pushing out the jack easier.