input: Write a python function to simulate exploring a dungeon, providing random room descriptions.
  assert explore_dungeon() in ['You find a dark and cramped room.', 'You enter a large and well lit chamber.', 'You enter a room with a small river running through it.']
  assert explore_dungeon() in ['You find a dark and cramped room.', 'You enter a large and well lit chamber.', 'You enter a room with a small river running through it.']
  assert explore_dungeon() in ['You find a dark and cramped room.', 'You enter a large and well lit chamber.', 'You enter a room with a small river running through it.']
output: import random
  
  def explore_dungeon():
      rooms = [
          'You find a dark and cramped room.',
          'You enter a large and well lit chamber.',
          'You enter a room with a small river running through it.'
      ]
      return random.choice(rooms)