chore(ckeditor5-math): initialize empty plugin

packages/ckeditor5-math/src/augmentation.ts

@@ -0,0 +1,7 @@
+import type { Math } from './index.js';
+
+declare module '@ckeditor/ckeditor5-core' {
+	interface PluginsMap {
+		[ Math.pluginName ]: Math;
+	}
+}

packages/ckeditor5-math/src/index.ts

@@ -0,0 +1,8 @@
+import ckeditor from './../theme/icons/ckeditor.svg';
+import './augmentation.js';
+
+export { default as Math } from './math.js';
+
+export const icons = {
+	ckeditor
+};

packages/ckeditor5-math/src/math.ts

@@ -0,0 +1,39 @@
+import { Plugin, ButtonView } from 'ckeditor5';
+
+import ckeditor5Icon from '../theme/icons/ckeditor.svg';
+
+export default class Math extends Plugin {
+	public static get pluginName() {
+		return 'Math' as const;
+	}
+
+	public init(): void {
+		const editor = this.editor;
+		const t = editor.t;
+		const model = editor.model;
+
+		// Register the "math" button, so it can be displayed in the toolbar.
+		editor.ui.componentFactory.add( 'math', locale => {
+			const view = new ButtonView( locale );
+
+			view.set( {
+				label: t( 'Math' ),
+				icon: ckeditor5Icon,
+				tooltip: true
+			} );
+
+			// Insert a text into the editor after clicking the button.
+			this.listenTo( view, 'execute', () => {
+				model.change( writer => {
+					const textNode = writer.createText( 'Hello CKEditor 5!' );
+
+					model.insertContent( textNode );
+				} );
+
+				editor.editing.view.focus();
+			} );
+
+			return view;
+		} );
+	}
+}