input: Write a python function to analyze the sentiment of a given text and return a sentiment score using the SentimentIntensityAnalyzer.
  assert sentiment_rating("I love this product! It's absolutely wonderful.") > 0
  assert sentiment_rating("I hate this product! It's the worst thing I've ever bought.") < 0
  assert sentiment_rating("This product is okay, not great but not terrible.") == 0
output: def sentiment_rating(text):
      from nltk.sentiment.vader import SentimentIntensityAnalyzer
      import nltk
      nltk.download('vader_lexicon')
      
      analyzer = SentimentIntensityAnalyzer()
      sentiment_score = analyzer.polarity_scores(text)['compound']
      
      if sentiment_score > 0:
          return 1
      elif sentiment_score < 0:
          return -1
      else:
          return 0