Implemented a new algorithm(Shell Sort) with Documentation.

[nishamehra]

Shell sort is often termed as an improvement over insertion sort. In insertion sort, we take increments by 1 to compare elements and put them in their proper position.

In shell sort, the list is sorted by breaking it down into a number of smaller sublists. It’s not necessary that the lists need to be with contiguous elements. Instead, shell sort technique uses increment i, which is also called “gap” and uses it to create a list of elements that are “i” elements apart.

[DakshKK]

Can you please re-write your markdown file, since it is not rendering anything, and that is not how markdown works. You can checkout the GFM syntax, and see how to write a proper README. And add proper documentation. Please follow our contribution guidelines.

[nishamehra]

Okay, I'll change the format of markdown file.