> bubble_sort([4,3,78,2,0,2])
=> [0,2,2,3,4,78]

• The function is called with one argument, an array
with random numbers.
• Use the function `downto` to go from array size minus two to zero, this function iterates the given block, passing in decreasing values from int down to and including limit. #=> `int.downto(limit)`
• So, to go from (array.size - 2) to zero and I declare the parameter `i` in the callback, we need it to be like this so as not to exceed the size of the array in the tour, we will explain in more detail later.
• In the next line, use the function `upto` to go from zero to `i`, this function iterates the given block, passing in integer values from int up to and including limit, #=> `int.upto(limit)`
• Taking `i` as the limit of the` upto` function, we ensure the last ordered value.
• And I declare the parameter `j` in the callback, which we will use as the array index for our algorithm.
• At this point, we have consecutive elements, let's see:
  - We have an array => array = [5,4,3]
  - So array[j] is equal to array[0] = 5
  - And array[j 1] is equal to array[1] = 4
• Then asking if first value greater than the second value, if true the following will happen:
  - Save to first value in the varible `temp` #=> temp = array[j]
  - Replace the value of the first for the second #=> array[j] = array[j 1]
  - Then change the value of the second for the temp #=> array[j 1] = temp
  - Our array would be like this, in the first iteration inside `upto` function #=> [4,5,3]
• So our algorithm will advance in pairs of two ordering it until it reaches the position `i`, 
• When done it would be like this. #=> [4,3,5]
• I'm still inside the `downto` block so I repeat the process, but this time the last element is ignored because it is already ordered.
• And that is what is known as the bubble sort.