Add example to README.md (#5)

Co-authored-by: Stephen <[email protected]>

README.md

@@ -1,6 +1,16 @@
 # Cross Subnet Virtual Machine (XSVM)
 
-Cross Subnet Asset Transfers
+Cross Subnet Asset Transfers README Overview
+
+[Background](#avalanche-subnets-and-custom-vms)
+
+[Introduction](#introduction)
+
+[Usage](#how-it-works)
+
+[Running](#running-the-vm)
+
+[Demo](#cross-subnet-transaction-example)
 
 ## Avalanche Subnets and Custom VMs
 
@@ -286,3 +296,82 @@ You can do this by following the [subnet tutorial] or by using the [subnet-cli].
 [Coreth]: https://github.com/ava-labs/coreth
 [C-Chain]: https://docs.avax.network/learn/platform-overview/#contract-chain-c-chain
 [Subnet]: https://docs.avax.network/learn/platform-overview/#subnets
+
+## Cross Subnet Transaction Example
+
+The following example shows how to interact with the XSVM to send and receive native assets across subnets.
+
+### Overview of Steps
+
+1. Create & deploy Subnet A
+2. Create  & deploy Subnet B
+3. Issue an **export** Tx on Subnet A
+4. Issue an **import** Tx on Subnet B
+5. Confirm Txs processed correctly
+
+> **Note:**  This demo requires [avalanche-cli](https://github.com/ava-labs/avalanche-cli) version > 1.0.5, [xsvm](https://github.com/ava-labs/xsvm) version > 1.0.2 and [avalanche-network-runner](https://github.com/ava-labs/avalanche-network-runner) v1.3.5.
+
+### Create and Deploy Subnet A, Subnet B
+
+Using the avalanche-cli, this step deploys two subnets running the XSVM. Subnet A will act as the sender in this demo, and Subnet B will act as the receiver.
+
+Steps
+
+Build the [XSVM](https://github.com/ava-labs/xsvm)
+
+### Create a genesis file
+
+```bash
+xsvm chain genesis --encoding binary > xsvm.genesis
+```
+
+### Create Subnet A and Subnet B
+
+```bash
+avalanche subnet create subnetA --custom --genesis <path_to_genesis> --vm <path_to_vm_binary>
+avalanche subnet create subnetB --custom --genesis <path_to_genesis> --vm <path_to_vm_binary>
+```
+
+### Deploy Subnet A and Subnet B
+
+```bash
+avalanche subnet deploy subnetA --local
+avalanche subnet deploy subnetB --local
+```
+
+### Issue Export Tx from Subnet A
+
+The SubnetID and ChainIDs are stored in the sidecar.json files in your avalanche-cli directory. Typically this is located at $HOME/.avalanche/subnets/
+
+```bash
+xsvm issue export --source-chain-id <SubnetA.BlockchainID> --amount <export_amount> --destination-chain-id <SubnetB.BlockchainID>
+```
+
+Save the TxID printed out by running the export command.
+
+### Issue Import Tx from Subnet B
+
+> Note: The import tx requires **snowman++** consensus to be activated on the importing chain. A chain requires ~3 blocks to be produced for snowman++ to start.
+> Run `xsvm issue transfer --chain-id <SubnetB.BlockchainID> --amount 1000`  to issue simple Txs on SubnetB
+
+```bash
+xsvm issue import --source-chain-id <SubnetA.BlockchainID> --destination-chain-id <SubnetB.BlockchainID> --tx-id <exportTxID> --source-uris <source_uris>
+```
+
+> The <source_uris> can be found by running `avalanche network status`. The default URIs are
+"http://localhost:9650,http://localhost:9652,http://localhost:9654,http://localhost:9656,http://localhost:9658"
+
+**Account Values**
+To check proper execution, use the `xsvm account` command to check balances.
+
+Verify the balance on SubnetA decreased by your export amount using
+
+```bash
+xsvm account --chain-id <SubnetA.BlockchainID>
+```
+
+Now verify chain A's assets were successfully imported to SubnetB
+
+```bash
+xsvm account --chain-id <SubnetB.BlockchainID> --asset-id <SubnetA.BlockchainID>
+```