New Edition

There are significant expansions of content to the book, and now I was able to use this for a full quarter of Principles of MRI instruction as the sole textbook.
Almost all code has now been converted to python as well.

Formatting and Plotting Fixes

Fixed minor formatting and plotting issues

Functions library and initial jupyter book version

The function content has been relatively stable for several years. This version now contains a jupyter book to collect and host all the notebooks developed for walking through concepts