Add info on how to build AssetBundles

[legoandmars]

There's a basic unity template people have been using here: https://github.com/EvaisaDev/LethalCompanyUnityTemplate

[Heyimmodding]

Reminder that this project doesn't have much to do with assetbundles alone but more in editor content creation. A basic assetbundle making guide should be more than good enough

[Boxofbiscuits97]

I should be picking this up tomorrow with @stoneman2 from the discord

[Heyimmodding]

Uh, I'm still working on my section for unity stuff that involves this

[Xilophor]

Added in #66