Implementation of the algorithm for the Koch snowflake (#4207)

* Add files via upload

Implementation of the algorithm for the Koch snowflake

* added underscore to variable names

* added newline and comment

I fixed the sorting of the imports and I added a comment to the plot-function to explain what it does and why it doesn't use a doctest. Thank you to user mrmaxguns for suggesting these changes.

* fixed accidental newline in the middle of expression

* improved looping

* moved "koch_snowflake.py" from "other" to "graphics"

* Update koch_snowflake.py

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