Fix docstring (TheAlgorithms#6461)

* fixed wrong algo name to radix sort

* added wiki url

* Added "source" in docstring

* Update radix_sort.py

Co-authored-by: Christian Clauss <cclauss@me.com>

Author: debjit-bw

sorts/radix_sort.py

@@ -1,11 +1,7 @@
 """
-This is a pure Python implementation of the quick sort algorithm
-For doctests run following command:
-python -m doctest -v radix_sort.py
-or
-python3 -m doctest -v radix_sort.py
-For manual testing run:
-python radix_sort.py
+This is a pure Python implementation of the radix sort algorithm
+
+Source: https://en.wikipedia.org/wiki/Radix_sort
 """
 from __future__ import annotations