Docstring for `image_processing.py`

[tlentali]

In order to reach the highest pylint note, I added some doc-string in each beginning of each script.
But I didn't fill it correctly.

pycht/pycht/image_processing.py

Lines 1 to 3 in 31e3e53

	"""
	Project settings
	"""

Sould be :

Provide the necessary code to generate a clustering, here a `kmeans` model, that will separate the different stencils by color.

It should serve as a quick reference to all the functions and arguments.

Docstring format :

• what are the most common python docstring formats
• styleguide

[clurton-betclic]

I'll have a look!