message: Change to extend building
diff: +import { Building } from '../../../lib/buildings/_common'
  +import { NPC } from '../../../lib/npc-generation/_common'
  +
  interface Setup {
  createSmithy(town: Town, opts?: Partial<Smithy>): Smithy
  }
  -export interface Smithy {
  +export interface Smithy extends Building {
  + associatedNPC: NPC
  wordNoun: string
  passageName: string
  initPassage: string
  