title: Write the function that finds the index of an element in array of numbers
body: <p>I made this to find the minimum value of the array of numbers:</p>
  
  <p><code>lst = [3, 71, 420, 14]
  print ("Min number in array:", min(lst))</code></p>
  
  <p>But how do I find the index of an element in array of numbers?</p>