Add syntax highlighter for .dart files
Add syntax highlighter for .dart files

ahmadassaf/Codebox,kustomzone/codebox,lcamilo15/codebox,code-box/codebox,indykish/codebox,quietdog/codebox,LogeshEswar/codebox,rodrigues-daniel/codebox,Ckai1991/codebox,smallbal/codebox,kustomzone/codebox,etopian/codebox,ronoaldo/codebox,nobutakaoshiro/codebox,lcamilo15/codebox,CodeboxIDE/codebox,etopian/codebox,smallbal/codebox,listepo/codebox,ahmadassaf/Codebox,fly19890211/codebox,LogeshEswar/codebox,fly19890211/codebox,rodrigues-daniel/codebox,rajthilakmca/codebox,listepo/codebox,CodeboxIDE/codebox,blubrackets/codebox,indykish/codebox,quietdog/codebox,rajthilakmca/codebox,blubrackets/codebox,code-box/codebox,ronoaldo/codebox,Ckai1991/codebox,nobutakaoshiro/codebox