DIALOGUE!

Added craploads of dialogue, up through Viridian Forest. Also added
support for active replacements of specific variables, namely ones that
begin with ‘$’. For example, $PLAYER is replaced by the player’s name,
$RIVAL with their name, etc.

There is also now a new class in framework.py called starter_poke(),
which contains three slots. These are the three poke balls that Oak
has, and changing any of these entries updates what is in the poke
balls and what he says when you want one.