add initial marp implementation with sample content and build configuration

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

@@ -0,0 +1,8 @@
+import { Variable } from './variable.js';
+export declare class VariablePool<T> {
+    private pool;
+    insert(variable: Variable<T>): void;
+    lookup(name: string): Variable<T>;
+    remove(name: string): void;
+    update(): void;
+}