started adding some documentation to modules
+r"""
+===============================================================================
+Metrics
+===============================================================================
+A suite of tools for determine key metrics about an image, including:
+
+``porosity`` - Quickly determines the ratio of void voxels to total voxels
+of the image.
+"""
from .__cld__ import chord_length_distribution
from .__tpc__ import two_point_correlation
from .__psf__ import pore_size_function
