docs(contributing.md): Link directly to conventions.md
docs(contributing.md): Link directly to conventions.md

TomNeyland/ng-chartist.js,demokracie21/angular-chartist.js,willsoto/angular-chartist.js,TomNeyland/ng-chartist.js,demokracie21/angular-chartist.js,paradox41/angular-chartist.js,paradox41/angular-chartist.js,willsoto/angular-chartist.js