[sorting] added flash sort algorithm

[gastonche]

Flashsort is a distribution sorting algorithm showing linear computational complexity O(n) for uniformly distributed data sets and relatively little additional memory requirement. The original work was published in 1998 by Karl-Dietrich Neubert. The basic idea behind flashsort is that in a data set with a known distribution, it is easy to immediately estimate where an element should be placed after sorting when the range of the set is known.

[abranhe]

Thank you for contributing to @AllAlgorithms, your pr got merged! ✨

Make sure that you ⭐️ the project 🤓, and continue helping us!

We are happy to merge your pull request but first, it needs to fix:

• remove .gitignore
• remove docs (sorting/README.md) all docs for algorithms should be added to AllAlgorithms/algorithms (you should open a pull request there ;))

we are waiting for your changes

[gastonche]

Okay, Will do that pretty soon @abranhe