Added space at end of file + at another return

Corrected some of the function docs.

Adjusted the spacing of the functions to be more PEP friendly.

A script demonstrating heapsort using a max heap has been added.
Comments have been added, describing the steps.

#1
selectionsort

Improved version of the bubble-sort method.

minor changes

The selection sort algorithm sorts an array by repeatedly finding the minimum element (considering ascending order) from unsorted part and putting it at the beginning. The algorithm maintains two subarrays in a given array.

1) The subarray which is already sorted.
2) Remaining subarray which is unsorted.

In every iteration of selection sort, the minimum element (considering ascending order) from the unsorted subarray is picked and moved to the sorted subarray.

Bubble Sort is the simplest sorting algorithm that works by repeatedly swapping the adjacent elements if they are in wrong order.

Basically in merge sort we use slice function so the above code is similat to quick sort which helps merge sort to use without slicing