Nerf Deathtrooper Blaster Barrel Extension

An extension for the Nerf Deathtrooper Blaster to make it _slightly_ more accurate.
Blaster will not fully function after this is attached as one of the dart barrels is partially covered.

**Versions**
I made two versions, one with a thicker alignment part as I can foresee it breaking under some circumstances. The difference is the inner diameter of the barrel is smaller on v2, which allows the wall to be thicker.
- e-11-d_nerf_barrel_extension.stl has a 0.8mm thick wall to align the part i