Resolves #121 Markdown card support

lib/ui_class/card.class.dart

@@ -12,6 +12,7 @@ class HACard {
   bool showEmpty;
   int columnsCount;
   List stateFilter;
+  String content;
 
   HACard({
     this.name,
@@ -22,6 +23,7 @@ class HACard {
     this.showState: true,
     this.stateFilter: const [],
     this.showEmpty: true,
+    this.content,
     @required this.type
   });
 

lib/ui_class/sizes_class.dart

@@ -11,6 +11,7 @@ class Sizes {
   static const nameFontSize = 15.0;
   static const smallFontSize = 14.0;
   static const largeFontSize = 24.0;
+  static const mediumFontSize = 21.0;
   static const inputWidth = 160.0;
   static const rowPadding = 10.0;
 }