Added functions relating to a notes system
added an Upset Potential calculator

Trying to find a suitable algorithm/formula to determine a character's
predilection towards winning an upset when they are an underdog, and of
determining their potential of losing when they are the favorite.
Currently using a simple formula with the Elo probability * win.  win =
1 for no upset, win = -1 for an upset.
Split find_matches() into matches_UI and find_match().

matches_UI() takes user input and calls find_match() using the input as
parameters.
Implemented Upset Potential into find_match()

also added a not-yet-working version of the notes_ui in find_match