input: Write a python function to generate and return the first N prime numbers.
  assert generate_primes(5) == [2, 3, 5, 7, 11]
  assert generate_primes(10) == [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
  assert generate_primes(0) == []
output: def generate_primes(N):
      if N == 0:
          return []
      
      primes = []
      num = 2
      while len(primes) < N:
          for i in primes:
              if num % i == 0:
                  break
          else:
              primes.append(num)
          num += 1
      return primes