XTLW6 - IDEX Cable Chain Mod

This is tagged as a work in progress; some sanding and trimming may be required here and there to ensure clearances.
What I know needs work:
- There is one incorrect T-nut on the left side of chain_anchors I believe; just trim this off and the rest should slide in!
- The hotend mounts may need some slight sanding to make sure they don't rub against the Y carriage when moving; I may have fixed this in the previous update but clearances are tight so this depends on your printer's accuracy.

For "L+R_hotend-chain-mount.stl" print with the flat edge of the two attachment prongs facing towards the build plate, and with supports. These are attached to the carriage using the two existing (M5?) bolts. There are 4 extra holes on the bottom of the part to fit 15mm M3 bolts that reinforce the fragile arms of the part if needed; the part isn't load-bearing so this is just a precaution.

For the "chain_anchors.stl", print with flat parts facing down, and with supports. This can be attache