Add create AMM tutorial

Add an interactive tutorial for creating an automated market maker,
updated with the latest changes from the Ripple Open Source site.

content/_code-samples/create-amm/js/connect.js

@@ -0,0 +1,18 @@
+// In browsers, use a <script> tag. In Node.js, uncomment the following line:
+// const xrpl = require('xrpl')
+
+const WS_URL = 'wss://amm.devnet.rippletest.net:51233/'
+const EXPLORER = 'amm-devnet.xrpl.org' // Optional, for linking
+
+async function main() {
+  // Define the network client
+  const client = new xrpl.Client(WS_URL)
+  await client.connect()
+
+  // ... custom code goes here
+
+  // Disconnect when done (If you omit this, Node.js won't end the process)
+  await client.disconnect()
+}
+
+main()