no longer distribute the bootstrap.css.map file (#2009)

Author: devoncarew

lib/resources/css/bootstrap.css.map

@@ -3,7 +3,6 @@
 const List<String> resource_names = [
   'package:dartdoc/resources/URI.js',
   'package:dartdoc/resources/css/bootstrap.css',
-  'package:dartdoc/resources/css/bootstrap.css.map',
   'package:dartdoc/resources/css/bootstrap.min.css',
   'package:dartdoc/resources/favicon.png',
   'package:dartdoc/resources/github.css',