Simpler hot-end

This hot end is the result of my attempt to build the Wildseyed Simple Hot End by jcabrer for my Simpler repstrap. I live in Metric land, along with the ROW (rest of the world) which started my journey down the path less taken to begin with...

I noticed that it would be possible to use the previously unused M6 thread on the MIG tip to our advantage, and make the tip itself easily exchangeable. This design also makes the fitting of the PTFE easier and more precisely aligned than I could mana