I found two incorrect entries for strokes on the M page with respect to Plover's current dictionary.

1. PHAUL outputs mall instead of maul .
2. PH-BG outputs {Mc^}{-|} instead of mechanic.

The second one didn't seem to have an obvious replacement since it's a multi-stroke word now which is why I'm making an issue instead of a pull request.

The word "theory" is used with a very specific meaning in this book, and appears both in the title and several times in the introduction, but it's only when one reaches the "What about other theories?" section that one starts getting a feel of what it actually means (and where the full expression "steno theory" appears for the first time).

As an absolute steno beginner, I think it would be helpful to somehow define this earlier, especially since the word is in the title of the book.