chore: wrap all code at 80 characters

Switch to the convention of using no trailing whitespace, even on blank lines. Also remove some unintended trailing whitespace on non-blank lines and fix a few typos.

Co-authored-by: Aaron Fenyes <aaron.fenyes@fareycircles.ooo>
Reviewed-on: #129
Reviewed-by: Vectornaut <vectornaut@nobody@nowhere.net>
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Co-committed-by: Glen Whitney <glen@studioinfinity.org>

notes/theory.md

@@ -22,8 +22,7 @@ Jürgen also emphasized the need for an intuitive user interface. Notes on that
 His final mathematical advice was reasonably encouraging, however:
 
 "But still I would consider it all more or less doable. One should very precisely think about a doable scope.
-I think three things are essential for the math no matter what you exactly
-plan.
+I think three things are essential for the math no matter what you exactly plan.
 
 1. Think projectively.
    Use Projective Geometry, Homogeneous Coordinates (or to a certain extent Quaternions, and Clifford Algebras, which are more or less an elegant way to merge Complex numbers with projective concepts.)