feat(editor): rewrite <i> to <em>

packages/ckeditor5-build-trilium/src/config.ts

@@ -59,6 +59,7 @@ import { Style } from "../../ckeditor5-style";
 import MentionCustomization from './mention_customization';
 import UploadimagePlugin from './uploadimage';
 import InternalLinkPlugin from './internallink';
+import ItalicAsEmPlugin from './italic_as_em';
 import MarkdownImportPlugin from './markdownimport';
 import CuttonotePlugin from './cuttonote';
 import IncludeNote from './includenote';
@@ -135,6 +136,7 @@ export const COMMON_PLUGINS = [
 	FindAndReplace,
 	Mention,
 	InternalLinkPlugin,
+	ItalicAsEmPlugin,
 	MarkdownImportPlugin,
 	CuttonotePlugin,
 	MentionCustomization,

packages/ckeditor5-build-trilium/src/italic_as_em.ts

@@ -0,0 +1,15 @@
+import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
+
+export default class ItalicAsEmPlugin extends Plugin {
+
+	init() {
+		this.editor.conversion
+			.for("downcast")
+			.attributeToElement({
+				model: "italic",
+				view: "em",
+				converterPriority: "high"
+			});
+	}
+
+}