chore: Update docs

examples/ActivityMessage.js

@@ -0,0 +1,15 @@
+const { Client } = require('../src/index');
+const client = new Client();
+
+client.on('ready', async () => {
+  console.log(`${client.user.username} is ready!`);
+  const channel = client.channels.cache.get('id');
+  channel.send({
+    activity: {
+      type: 3, // MessageActivityType.Listen
+      partyId: `spotify:${client.user.id}`,
+    },
+  });
+});
+
+client.login('token');