Add a .gitjournal.yaml file in a folder

This file will be added to save the settings of how we want that folder
to behave. For example - default Editor, view, sorting mode, etc.

This feature is currently disabled as it will only be a part of the pro
mode.

test/notes_folder_config_test.dart

@@ -0,0 +1,43 @@
+import 'dart:io';
+
+import 'package:gitjournal/core/notes_folder_config.dart';
+import 'package:gitjournal/core/notes_folder_fs.dart';
+import 'package:gitjournal/core/sorting_mode.dart';
+import 'package:gitjournal/folder_views/common.dart';
+import 'package:gitjournal/folder_views/standard_view.dart';
+import 'package:gitjournal/screens/note_editor.dart';
+import 'package:path/path.dart' as p;
+import 'package:test/test.dart';
+
+void main() {
+  group('Notes Folder Config', () {
+    Directory tempDir;
+
+    setUp(() async {
+      tempDir = await Directory.systemTemp.createTemp('__notes_config_test__');
+    });
+
+    tearDown(() async {
+      tempDir.deleteSync(recursive: true);
+    });
+
+    test('Should load from FS correctly', () async {
+      var folder = NotesFolderFS(null, tempDir.path);
+      var config = NotesFolderConfig(
+        defaultEditor: EditorType.Checklist,
+        defaultView: FolderViewType.Standard,
+        showNoteSummary: true,
+        sortingMode: SortingMode.Modified,
+        viewHeader: StandardViewHeader.TitleOrFileName,
+        folder: folder,
+      );
+
+      await config.saveToFS();
+      var file = File(p.join(tempDir.path, NotesFolderConfig.FILENAME));
+      expect(file.existsSync(), true);
+
+      var config2 = await NotesFolderConfig.fromFS(folder);
+      expect(config, config2);
+    });
+  });
+}