Move combat shotguns earlier in the tech tree

[Cribbit]

I had assumed this was already suggested, but searching can't find direct topics on this. I see suggestions for shotgun turrets. I see people complaining that shotguns are useless, bar niche cases. Apologies if I just missed some old thread.

Proposed Changes

• Combat shotgun down to mil 2 (from 3)
• SMG up to mil 2 (from 1)
• Piercing ammo (both types) to own tech with red/green/grey sci & mil 2 required

These are all just changing the tech tree, no actual item changes.

Reasons

Shotgun over SMG has 2 advantages:

• More efficient on ammo, but that's not a concern when actively in combat
• Faster at killing spawners... if you're right next to it, with no biters left

Base shotgun is comparable to the pistol, not the SMG. Combat shotgun barely competes with the SMG.

By the time combat shotgun is unlocked at mil 3 (requires blue sci) far more effective options are available - rockets, capsules, tank, SMG & piercing ammo. It is an early game weapon that isn't unlocked until mid game.