Merge pull request #5 from Peach2Peach/update-readme

Update readme

README.md

@@ -53,16 +53,16 @@ cd ios && pod install
 
 ### Create a Wallet & sync the balance of a descriptor
 
-```js
+```ts
 import { DescriptorSecretKey, Mnemonic, Blockchain, Wallet, DatabaseConfig, Descriptor } from 'bdk-rn';
 import { WordCount, Network } from 'bdk-rn/lib/lib/enums';
 
 // ....
 
 const mnemonic = await new Mnemonic().create(WordCount.WORDS12);
 const descriptorSecretKey = await new DescriptorSecretKey().create(Network.Testnet, mnemonic);
-const externalDescriptor = await new Descriptor().newBip44(descriptorSecretKey, KeyChainKind.External, Network.Testnet);
-const internalDescriptor = await new Descriptor().newBip44(descriptorSecretKey, KeyChainKind.Internal, Network.Testnet);
+const externalDescriptor = await new Descriptor().newBip84(descriptorSecretKey, KeychainKind.External, Network.Testnet);
+const internalDescriptor = await new Descriptor().newBip84(descriptorSecretKey, KeychainKind.Internal, Network.Testnet);
 
 const config: BlockchainElectrumConfig = {
   url: 'ssl://electrum.blockstream.info:60002',
@@ -82,24 +82,34 @@ await wallet.sync(blockchain);
 
 ### Create a `public` wallet descriptor
 
-```js
+```ts
 import { DescriptorSecretKey, Mnemonic, Descriptor } from 'bdk-rn';
-import { WordCount, Network, KeyChainKind } from 'bdk-rn/lib/lib/enums';
+import { WordCount, Network, KeychainKind } from 'bdk-rn/lib/lib/enums';
 
 // ....
 
 const mnemonic = await new Mnemonic().create(WordCount.WORDS12);
 const descriptorSecretKey = await new DescriptorSecretKey().create(Network.Testnet, mnemonic);
 const descriptorPublicKey = await descriptorSecretKey.asPublic();
 const fingerprint = 'd1d04177';
-const externalPublicDescriptor = await new Descriptor().newBip44Public(
+const externalPublicDescriptor = await new Descriptor().newBip84Public(
   descriptorPublicKey,
   fingerprint,
   KeychainKind.External,
   Network.Testnet
 );
 ```
 
+### Store wallet data persistently
+```ts
+import RNFS from 'react-native-fs'
+import { DatabaseConfig, ... } from 'bdk-rn';
+
+// create sqlite database config with rn document directory path
+const dbConfig = await new DatabaseConfig().sqlite(`${RNFS.DocumentDirectoryPath}/bdk-wallet`)
+
+```
+
 ### References:
 - Setting up a local Esplora instance for testing:
 https://bitcoin.stackexchange.com/questions/116937/how-do-i-setup-an-esplora-instance-for-local-testing/116938#116938