Document how to use wrangle_matrix tool for tutorial

[cjgrady]

Document how to wrangle matrices using the wrangle_matrix tool and from a python script.

• [ ] Document how to use wrangle_matrix in sphinx docs
• [ ] Document how to wrangle matrices using a python script in sphinx docs
• [ ] Add pytest tests that replicate the instructions in the wrangle matrix sphinx docs

[zzeppozz]

Documentation in https://github.com/biotaphy/tutorials