Add main_features

This doesn't work as it requires flutter, but I may as well commit it

lib/main_features.dart

@@ -0,0 +1,22 @@
+import 'package:yaml_serializer/yaml_serializer.dart';
+
+import 'package:gitjournal/features.dart';
+
+// This doesn't work as this requires flutter
+void main() {
+  var all = <Map<String, dynamic>>[];
+  for (var feature in Features.all) {
+    all.add(_toMap(feature));
+  }
+
+  var yaml = toYAML({'features': all});
+  print(yaml);
+}
+
+Map<String, dynamic> _toMap(Feature feature) {
+  return {
+    "title": feature.title,
+    "date": feature.date,
+    "pro": feature.pro,
+  };
+}