Snapmaker 2.0 X Carriage Stiffener - cheaper remix

This is a minor remix. Read everything from the original.

When I went to get the parts for this, I found that the screws used were uncommon and more expensive. As such, I've made the following mods:

M5 x 85 are now M5x80mm long.
1/4-20 x 5 1/4" are now M6x130mm long.

These changes enabled me to use an M5 assorted screw set and get 10 M6 long bolts for nearly no increase in price. I use screws for other project so this was a win-win for me.

Note: this frame (like the original) is incompatible with the 10w laser. Perhaps this can be worked in the future but... it's not hard to remove.