refactor: organize sources by language directories

dart/manga/multisrc/madara/src/ru/bestmanga/bestmanga.dart

@@ -0,0 +1,15 @@
+import '../../../../../../../model/source.dart';
+
+Source get bestmangaSource => _bestmangaSource;
+
+Source _bestmangaSource = Source(
+  name: "BestManga",
+  baseUrl: "https://bestmanga.club",
+  lang: "ru",
+
+  typeSource: "madara",
+  iconUrl:
+      "https://raw.githubusercontent.com/kodjodevf/mangayomi-extensions/$branchName/dart/manga/multisrc/madara/src/ru/bestmanga/icon.png",
+  dateFormat: "dd.MM.yyyy",
+  dateFormatLocale: "ru",
+);