add mod.ts for deno

Author: gfx

example/deno-with-denoland.ts

@@ -0,0 +1,5 @@
+#!/usr/bin/env deno run
+/* eslint-disable no-console */
+import * as msgpack from "https://deno.land/x/msgpack_javascript/mod.ts";
+
+console.log(msgpack.decode(msgpack.encode("Hello, world!")));

mod.ts

@@ -0,0 +1 @@
+export * from "./dist.es5+esm/index.mjs";

test/deno_test.ts

@@ -4,7 +4,7 @@
 import {
   assertEquals,
 } from "https://deno.land/std/testing/asserts.ts";
-import * as msgpack from "../dist.es5+esm/index.mjs";
+import * as msgpack from "../mod.ts";
 
 Deno.test("Hello, world!", () => {
   const encoded = msgpack.encode("Hello, world!");