Reflow STYLEGUIDE.md
Reflow STYLEGUIDE.md

If we say that text should be wrapped at 72 characters, might as well
do that in the styleguide itself…

perl6/doc,stmuk/doc,tbrowder/doc,stmuk/doc,tbrowder/doc,stmuk/doc,dmaestro/doc,jonathanstowe/doc,tbrowder/doc,jonathanstowe/doc,perl6/doc,MasterDuke17/doc,stmuk/doc,dmaestro/doc,tbrowder/doc,dmaestro/doc,perl6/doc,jonathanstowe/doc,MasterDuke17/doc,MasterDuke17/doc,stmuk/doc,perl6/doc,dmaestro/doc,MasterDuke17/doc,jonathanstowe/doc,dmaestro/doc,jonathanstowe/doc,perl6/doc