input: Write a function that takes a website URL as input and crawls the website to extract all phone numbers matching the pattern '\d{3}-\d{3}-\d{4}'. The function should return a list of phone numbers found on the website. If no phone numbers are found, return an empty list.
  assert crawl_website_for_phone_numbers('www.example.com')==['123-456-7890', '987-654-3210']
output: import re
  import requests
  
  def crawl_website_for_phone_numbers(url):
      response = requests.get(url)
      if response.status_code != 200:
          return []
      phone_numbers = re.findall(r'\d{3}-\d{3}-\d{4}', response.text)
      return phone_numbers