MAINT: Configure the editor the same way as in WebUI

.gitignore

@@ -3,3 +3,4 @@ coverage/
 node_modules/
 tmp/
 sample/ckeditor.dist.js
+/package-lock.json

package.json

@@ -36,17 +36,17 @@
     "@ckeditor/ckeditor5-editor-classic": ">=32.0.0",
     "@ckeditor/ckeditor5-essentials": ">=32.0.0",
       "@ckeditor/ckeditor5-heading": ">=32.0.0",
+      "@ckeditor/ckeditor5-horizontal-line": ">=32.0.0",
     "@ckeditor/ckeditor5-image": ">=32.0.0",
-    "@ckeditor/ckeditor5-indent": ">=32.0.0",
     "@ckeditor/ckeditor5-inspector": "^2.2.2",
     "@ckeditor/ckeditor5-link": ">=32.0.0",
       "@ckeditor/ckeditor5-list": ">=32.0.0",
-    "@ckeditor/ckeditor5-media-embed": ">=32.0.0",
+          "@ckeditor/ckeditor5-markdown-gfm": ">=32.0.0",
     "@ckeditor/ckeditor5-package-tools": "^1.0.0-beta.4",
       "@ckeditor/ckeditor5-paragraph": ">=32.0.0",
+          "@ckeditor/ckeditor5-source-editing": ">=32.0.0",
     "@ckeditor/ckeditor5-table": ">=32.0.0",
     "@ckeditor/ckeditor5-theme-lark": ">=32.0.0",
-    "@ckeditor/ckeditor5-upload": ">=32.0.0",
     "eslint": "^7.32.0",
     "eslint-config-ckeditor5": ">=3.1.1",
     "http-server": "^14.1.0",

sample/ckeditor.js

 import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
 import CKEditorInspector from '@ckeditor/ckeditor5-inspector';
 
-import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials';
 import Autoformat from '@ckeditor/ckeditor5-autoformat/src/autoformat';
+import AutoImage from '@ckeditor/ckeditor5-image/src/autoimage.js';
 import BlockQuote from '@ckeditor/ckeditor5-block-quote/src/blockquote';
 import Bold from '@ckeditor/ckeditor5-basic-styles/src/bold';
+import Code from '@ckeditor/ckeditor5-basic-styles/src/code';
+import CodeBlock from '@ckeditor/ckeditor5-code-block/src/codeblock';
+import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials';
 import Heading from '@ckeditor/ckeditor5-heading/src/heading';
+import HorizontalLine from '@ckeditor/ckeditor5-horizontal-line/src/horizontalline.js';
 import Image from '@ckeditor/ckeditor5-image/src/image';
 import ImageCaption from '@ckeditor/ckeditor5-image/src/imagecaption';
 import ImageStyle from '@ckeditor/ckeditor5-image/src/imagestyle';
 import ImageToolbar from '@ckeditor/ckeditor5-image/src/imagetoolbar';
-import ImageUpload from '@ckeditor/ckeditor5-image/src/imageupload';
-import Base64UploadAdapter from '@ckeditor/ckeditor5-upload/src/adapters/base64uploadadapter';
-import Indent from '@ckeditor/ckeditor5-indent/src/indent';
 import Italic from '@ckeditor/ckeditor5-basic-styles/src/italic';
 import Link from '@ckeditor/ckeditor5-link/src/link';
 import List from '@ckeditor/ckeditor5-list/src/list';
-import MediaEmbed from '@ckeditor/ckeditor5-media-embed/src/mediaembed';
+import Markdown from '@ckeditor/ckeditor5-markdown-gfm/src/markdown.js';
 import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph';
+import SourceEditing from '@ckeditor/ckeditor5-source-editing/src/sourceediting.js';
+import Strikethrough from '@ckeditor/ckeditor5-basic-styles/src/strikethrough.js';
 import Table from '@ckeditor/ckeditor5-table/src/table';
 import TableToolbar from '@ckeditor/ckeditor5-table/src/tabletoolbar';
-import CodeBlock from '@ckeditor/ckeditor5-code-block/src/codeblock';
-import Code from '@ckeditor/ckeditor5-basic-styles/src/code';
+import TodoList from '@ckeditor/ckeditor5-list/src/todolist';
 
 import MathJaxCodeDelimiters from '../src/mathjax_code_delimiters';
 
@@ -31,52 +33,55 @@ ClassicEditor
 	.create( document.querySelector( '#editor' ), {
 		plugins: [
 			MathJaxCodeDelimiters,
-			Essentials,
 			Autoformat,
+			AutoImage,
 			BlockQuote,
 			Bold,
+			Code,
+			CodeBlock,
+			Essentials,
 			Heading,
+			HorizontalLine,
 			Image,
 			ImageCaption,
 			ImageStyle,
 			ImageToolbar,
-			ImageUpload,
-			Indent,
 			Italic,
 			Link,
 			List,
-			MediaEmbed,
+			Markdown,
 			Paragraph,
+			SourceEditing,
+			Strikethrough,
 			Table,
 			TableToolbar,
-			CodeBlock,
-			Code,
-			Base64UploadAdapter
+			TodoList
 		],
 		toolbar: [
-			'inlineMathButton',
-			'displayMathButton',
+			'sourceEditing',
 			'|',
+			'undo',
+			'redo',
 			'heading',
 			'|',
 			'bold',
 			'italic',
+			'strikethrough',
+			'|',
+			'horizontalLine',
 			'link',
-			'code',
+			'blockQuote',
+			'insertTable',
+			'|',
 			'bulletedList',
 			'numberedList',
+			'todoList',
 			'|',
-			'outdent',
-			'indent',
-			'|',
-			'uploadImage',
-			'blockQuote',
-			'insertTable',
-			'mediaEmbed',
+			'code',
 			'codeBlock',
 			'|',
-			'undo',
-			'redo'
+			'inlineMathButton',
+			'displayMathButton'
 		],
 		image: {
 			toolbar: [ 'imageStyle:inline', 'imageStyle:block', 'imageStyle:side', '|', 'imageTextAlternative' ]