Refactor Send XRP: reliable sub, folders by language

- Use reliable transaction submission methods where available
- Update text to describe the functions (esp. xrpl.js 2.0 stuff)
- Move Send XRP code samples to subfolders by language for consistency
  with other tutorials

content/_code-samples/send-xrp/js/send-xrp.js

@@ -0,0 +1,53 @@
+// Dependencies for Node.js.
+// In browsers, use a <script> tag instead.
+if (typeof module !== "undefined") {
+  // gotta use var here because const/let are block-scoped to the if statement.
+  var xrpl = require('xrpl')
+}
+
+// Example credentials
+const wallet = xrpl.Wallet.fromSeed("sn3nxiW7v8KXzPzAqzyHXbSSKNuN9")
+
+// Connect -------------------------------------------------------------------
+async function main() {
+  console.log("Connecting to Testnet...")
+  const api = new xrpl.Client('wss://s.altnet.rippletest.net:51233')
+  await api.connect()
+
+  // Get credentials from the Testnet Faucet -----------------------------------
+  console.log("Getting a wallet from the Testnet faucet...")
+  const {wallet, balance} = await api.fundWallet()
+
+  // Prepare transaction -------------------------------------------------------
+  const prepared = await api.autofill({
+    "TransactionType": "Payment",
+    "Account": wallet.address,
+    "Amount": xrpl.xrpToDrops("22"),
+    "Destination": "rPT1Sjq2YGrBMTttX4GZHjKu9dyfzbpAYe"
+  })
+  const max_ledger = prepared.LastLedgerSequence
+  console.log("Prepared transaction instructions:", prepared)
+  console.log("Transaction cost:", xrpl.dropsToXrp(prepared.Fee), "XRP")
+  console.log("Transaction expires after ledger:", max_ledger)
+
+  // Sign prepared instructions ------------------------------------------------
+  const signed = wallet.sign(prepared)
+  console.log("Identifying hash:", signed.hash)
+  console.log("Signed blob:", signed.tx_blob)
+
+  // Submit signed blob --------------------------------------------------------
+  const tx = await api.submitSignedReliable(signed.tx_blob)
+  // This raises an exception if the transaction isn't confirmed.
+
+  // Wait for validation -------------------------------------------------------
+  // submitSignedReliable() handles this automatically, but it can take 4-7s.
+
+  // Check transaction results -------------------------------------------------
+  console.log("Transaction result:", tx.result.meta.TransactionResult)
+  console.log("Balance changes:", JSON.stringify(xrpl.getBalanceChanges(tx.result.meta), null, 2))
+
+  // End of main()
+  api.disconnect()
+}
+
+main()