add initial marp implementation with sample content and build configuration

node_modules/mj-context-menu/js/item_submenu.d.ts

@@ -0,0 +1,26 @@
+import { AbstractItem } from './abstract_item.js';
+import { Menu } from './menu.js';
+import { ParserFactory } from './parser_factory.js';
+export declare class Submenu extends AbstractItem {
+    private span;
+    private _submenu;
+    static fromJson(factory: ParserFactory, { content: content, menu: submenu, id: id }: {
+        content: string;
+        menu: any;
+        id: string;
+    }, menu: Menu): Submenu;
+    constructor(menu: Menu, content: string, id?: string);
+    set submenu(menu: Menu);
+    get submenu(): Menu;
+    mouseover(event: MouseEvent): void;
+    mouseout(event: MouseEvent): void;
+    unfocus(): void;
+    focus(): void;
+    executeAction(): void;
+    generateHtml(): void;
+    left(event: KeyboardEvent): void;
+    right(event: KeyboardEvent): void;
+    toJson(): {
+        type: string;
+    };
+}