Chestplate Elytra [Datapack] Update for 1.16+

THIS IS NOT MY ORIGINAL WORK. ALL CREDITS GO TO DAMINATOR4113 AND KIKIPUNK. I HAVE ONLY ADDED SUPPORT FOR 1.16+ WITH NETHERITE ARMOUR. 

The original work can be found here along with the instructions on how to use.

https://www.curseforge.com/minecraft/customization/chestplate-elytra 

 Please note that when combining a Netherite Chestplate and Elytra, its durability will be halved.  It can still be repaired by mending and phantom membranes, but I have no way of fixing it as I really dont know how the datapack works, I only copy and pasted some lines and replaced Diamond_Chestplate with Netherite_Chestplate