add example that works with node.js

README.md

···
 
 [anproto.com](https://anproto.com)
 
-+ [Deno/Browser implementation](https://github.com/evbogue/anproto) [by Evbogue]
++ [JavaScript implementation](https://github.com/evbogue/anproto) [by Evbogue]
 + [Golang implementation](https://github.com/vic/goan) [by Vic]
 
 try it at [anproto.com/try](https://anproto.com/try) or use a client such as [wiredove](https://wiredove.net/)

ex.js

···
 const m = "Hello World";
 const h = await an.hash(m);
 const k = await an.gen();
-const s = await an.sign(m, k);
+const s = await an.sign(h, k);
 const o = await an.open(s);
 
 console.log(k);

node_ex.js

···
+// get an.js working in Node.js -- from  https://github.com/vic/goan/blob/main/js_helper.js
+
+import { createRequire } from 'module';
+const require = createRequire(import.meta.url);
+
+globalThis.self = {
+  crypto: {
+    getRandomValues: (buf) => {
+      require('crypto').randomFillSync(buf);
+      return buf;
+    }
+  }
+};
+
+if (typeof globalThis.crypto === 'undefined' || typeof globalThis.crypto.subtle === 'undefined') {
+  globalThis.crypto = globalThis.crypto || {};
+  try {
+    globalThis.crypto.subtle = require('crypto').webcrypto.subtle;
+  } catch (e) {
+    console.log(e)
+  }
+}
+
+const { an } = await import('./an.js');
+
+const m = "Hello World";
+const h = await an.hash(m);
+const k = await an.gen();
+const s = await an.sign(h, k);
+const o = await an.open(s);
+
+console.log(k);
+console.log(h);
+console.log(s);
+console.log(o);