too much work … just find a way to concatenate

src/addons/zmodem/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "target": "es6",
+    "rootDir": ".",
+    "outDir": "../../../lib/addons/zmodem/",
+    "sourceMap": true,
+    "removeComments": true
+  }
+}

src/addons/zmodem/zmodem.ts

@@ -1,3 +1,11 @@
+import { Zmodem } from '../../../node_modules/zmodem.js/dist/zmodem.js';
+
+declare var exports: any;
+declare var module: any;
+declare var define: any;
+declare var require: any;
+declare var window: any;
+
 /**
  *
  * Allow xterm.js to handle ZMODEM uploads and downloads.