input: Write a python function to create a Document Term Matrix (DTM) from a list of documents using 'gensim'.
  assert create_dtm(['The cat is an adorable pet.', 'Dogs are loyal animals.']) == [[(0, 1), (1, 1), (2, 1), (3, 1), (4, 1)], [(5, 1), (6, 1), (7, 1), (8, 1)]]
  assert create_dtm(['Cats purr.', 'Dogs bark.']) == [[(0, 1), (1, 1)], [(2, 1), (3, 1)]]
output: def create_dtm(documents):
      from gensim import corpora
      
      # Tokenize the documents
      tokenized_documents = [doc.lower().split() for doc in documents]
      
      # Create a dictionary representation of the documents
      dictionary = corpora.Dictionary(tokenized_documents)
      
      # Create the Document-Term Matrix
      dtm = [dictionary.doc2bow(doc) for doc in tokenized_documents]
      
      return dtm