input: def linearSearch(arr: list, value: int) -> int:
      """
      Create an algorithm for a linear search. The algorithm should take in an array and a value to search for, and return the index of the value if it is found, or -1 if it is not.
      
      >>> arr = [5, 3, 7, 2]
      >>> searchValue = 7
      >>> linearSearch(arr, searchValue)
      2
      
      >>> arr = [5, 3, 7, 2]
      >>> searchValue = 4
      >>> linearSearch(arr, searchValue)
      -1
      """
output:     for i in range(len(arr)):
          if arr[i] == value:
              return i
      return -1