readme: add screenshot and functionality

Author: reez

BDKSwiftExampleWallet/Service/BDK Service/BDKService.swift

@@ -80,7 +80,7 @@ private class BDKService {
             changeDescriptor: changeDescriptor.asStringPrivate()
         )
         try keyService.saveBackupInfo(backupInfo)
-        let wallet = try Wallet.init(
+        let wallet = try Wallet(
             descriptor: descriptor,
             changeDescriptor: changeDescriptor,
             network: network,
@@ -90,7 +90,7 @@ private class BDKService {
     }
 
     private func loadWallet(descriptor: Descriptor, changeDescriptor: Descriptor) throws {
-        let wallet = try Wallet.init(
+        let wallet = try Wallet(
             descriptor: descriptor,
             changeDescriptor: changeDescriptor,
             network: network,

Docs/bitcoin-screen.png

@@ -1,5 +1,37 @@
 # BDKSwiftExampleWallet
-This is a Work in Progress.
 
 [![License](https://img.shields.io/badge/license-MIT%2FApache--2.0-blue.svg)](https://github.com/reez/BDKSwiftExampleWallet/blob/main/LICENSE)
 
+An example iOS app using [BDK](https://github.com/bitcoindevkit)
+
+<img src="Docs/bitcoin-screen.png" alt="Screenshot" width="236" height="511">
+
+## Functionality
+
+*This is an experimental work in progress.*
+
+### Wallet
+
+Supports single key HD segwit/bech32 wallets with BIP84 derivation paths. 
+
+`wpkh([extended private key]/84'/1'/0'/0/*)`
+
+### Implemented
+
+- [x] Create Wallet `Wallet(descriptor: changeDescriptor: network: databaseConfig:)`
+
+- [x] Get Address `getAddress`
+
+- [x] Get Balance `getBalance`
+
+- [x] List Transactions `listTransactions`
+
+- [x] Send `send`
+
+- [x] Sync `sync`
+
+## Swift Packages
+
+- [BDK Swift](https://github.com/bitcoindevkit/bdk-swift)
+
+- [BitcoinUI](https://github.com/reez/BitcoinUI)