Disassembly documentation

[Karol1223]

Summary

None

Purpose of change

Part of #73410 and probably the only one I can do myself

Describe the solution

Documentation regarding the different ways to handle item disassembly, how to choose the method, and what to look out for when adding new disassembly recipes or editing current ones

Link directly to the readable version https://github.com/Karol1223/Cataclysm-DDA/blob/disassembly-doc/doc/ITEM_DISASSEMBLY.md

Describe alternatives you've considered

Testing

Big Dev made me read the docs, by tricking me into reading my own work to make sure I wasn't lying.

Additional context

Since most of this information was already known to me I don't really know how helpful this is. I desperately need people to proofread this for me to make sure this is understandable and makes sense. And if there's anything else this doc should have, tell me and I'll see if it makes sense to add it.