Version 0.2.20

Version 0.2.20 

•   Chapter 1 mostly finished. Currently at ~30K words.
•   The demo ends after the prolog
•   The use of the word "prolog" instead of 'prologue' is being done intentionally.  "Prolog" is a logic programming language associated with artificial intelligence and computational linguistics. Added an explanation of the word to the intro to make that more clear.
•   Brings it many small fixes and fixes typos.
•   Adds a new font