input: Write a python function to search for a given keyword in a collection of documents.
  assert search([{'words': ['hello', 'world']}, {'words': ['python', 'code']}], 'hello') == [{'words': ['hello', 'world']}]
  assert search([{'words': ['test', 'case']}, {'words': ['another', 'test']}], 'test') == [{'words': ['test', 'case']}, {'words': ['another', 'test']}]
  assert search([{'words': ['apple', 'banana']}, {'words': ['cherry', 'date']}], 'pear') == []
output: def search(documents, keyword):
      return [doc for doc in documents if keyword in doc['words']]