Update README.fr.md - looks typo to my rusty french
Update README.fr.md - looks typo to my rusty french

My french isn't that good and hasn't been actively used in a while but after googling `exéxutez` still looks like a typo.
stmuk/doc,dmaestro/doc,perl6/doc,perl6/doc,dmaestro/doc,MasterDuke17/doc,stmuk/doc,dmaestro/doc,tbrowder/doc,jonathanstowe/doc,stmuk/doc,MasterDuke17/doc,jonathanstowe/doc,MasterDuke17/doc,perl6/doc,MasterDuke17/doc,stmuk/doc,perl6/doc,tbrowder/doc,tbrowder/doc,jonathanstowe/doc,perl6/doc,jonathanstowe/doc,stmuk/doc,jonathanstowe/doc,dmaestro/doc,tbrowder/doc,dmaestro/doc