Anet E10: Improved beltlock for heatbed

Improved belt lock for the heatbed on the Anet E10 printer.
Stock it's just 2 bolts which start flexing when you try to tension the belt, potentially damaging the frame.

This design uses the same 2 bolts to attach to the carriage but the plastic will take up the entire force instead of twisting the frame.

You can check out the videos about this upgrade here:
https://www.youtube.com/watch?v=1YHIuqbW_fg

You can currently get this printer quite cheap(279 USD/235EUR) via my affiliate link