chore: switch iOS steps, add pod update for existing projects (#59)

Signed-off-by: James Ebert <[email protected]>

README.md

@@ -149,16 +149,18 @@ Hermes is not required for older versions of React Native
 
 ## iOS
 
-1. Install CocoaPods dependencies:
+1. Add the following line to the start of your Podfile (`ios/Podfile`):
 
 ```
-pod install --project-directory=ios/
+source 'https://github.com/hyperledger/indy-sdk-react-native'
 ```
 
-2. Add the following line to the start of your Podfile (`ios/Podfile`):
+2. Install the Latest CocoaPods dependencies:
 
 ```
-source 'https://github.com/hyperledger/indy-sdk-react-native'
+cd ios
+pod install
+pod update Indy
 ```
 
 3. Configure Bitcode to `no` in both the project and targets