Organize and add events and add inventory types

[connerdouglass]

I really like this improvement! It might sound pedantic, but could we name the folders "block" and "entity", instead of "blocks" and "entities".

Also make sure to run npm run build:check to make sure all the other imports still point to the right place. I think there's one in src/entity/Entity.ts that needs updating.

Then I will merge it!