Seeing if packaging is irretrievably broken. Python 3.11 taking too long, removed.

• Added unweave.py, which contains code to guess the colourmap from an image file or RGB image array.
• Added two notebooks to the docs to illustrate how unweaving works.
• Updated unmap.unmap() to guess the colourmap if cmap=None.

Testing release

First working release with test and docs.