input: Write a python function to get synonyms of a word from a JSON file.
  assert get_synonyms('happy')==['joyful', 'content', 'cheerful']
  assert get_synonyms('sad')==['unhappy', 'sorrowful', 'dejected']
  assert get_synonyms('angry')==['mad', 'furious', 'irate']
output: def get_synonyms(word):
      import json
      
      with open('synonyms.json', 'r') as file:
          synonyms_dict = json.load(file)
          
      return synonyms_dict.get(word, [])