input: Write a function to create a search engine in Python to quickly search through a given array using linear search. If the search item is found, return its position. If the item is not found, return -1.
  assert linearSearch('hospital') == 1
  assert linearSearch('mall') == 3
  assert linearSearch('library') == -1
  assert linearSearch('school') == 0
  assert linearSearch('theatre') == 4
output: def linearSearch(arr, target):
      for i in range(len(arr)):
          if arr[i] == target:
              return i
      return -1