feat: integate appflowy_editor markdown codec into appflowy

frontend/app_flowy/lib/plugins/doc/application/share_bloc.dart

@@ -1,14 +1,14 @@
 import 'dart:convert';
 import 'dart:io';
 import 'package:app_flowy/plugins/doc/application/share_service.dart';
-import 'package:app_flowy/workspace/application/markdown/document_markdown.dart';
 import 'package:flowy_sdk/protobuf/flowy-document/entities.pb.dart';
 import 'package:flowy_sdk/protobuf/flowy-folder/view.pb.dart';
 import 'package:flowy_sdk/protobuf/flowy-error/errors.pb.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:dartz/dartz.dart';
-import 'package:appflowy_editor/appflowy_editor.dart' show Document;
+import 'package:appflowy_editor/appflowy_editor.dart'
+    show Document, documentToMarkdown;
 part 'share_bloc.freezed.dart';
 
 class DocShareBloc extends Bloc<DocShareEvent, DocShareState> {

frontend/app_flowy/packages/appflowy_editor/lib/appflowy_editor.dart

@@ -39,3 +39,4 @@ export 'src/plugins/markdown/encoder/parser/node_parser.dart';
 export 'src/plugins/markdown/encoder/parser/text_node_parser.dart';
 export 'src/plugins/markdown/encoder/parser/image_node_parser.dart';
 export 'src/plugins/markdown/decoder/delta_markdown_decoder.dart';
+export 'src/plugins/markdown/document_markdown.dart';

frontend/app_flowy/pubspec.lock

@@ -773,6 +773,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.0.2"
+  markdown:
+    dependency: transitive
+    description:
+      name: markdown
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "6.0.1"
   matcher:
     dependency: transitive
     description: