README.md in paddle-2.0.0 vs README.md in paddle-2.1.0

@@ -5,11 +5,11 @@
 ## Installation
 
 Add this line to your application's Gemfile:
 
 ```ruby
-gem "paddle", "~> 2.0"
+gem "paddle", "~> 2.1"
 ```
 
 ## Billing API
 
 For accessing the new Billing API from Paddle. For more info, view the [Paddle Billing](https://www.paddle.com/billing) page.
@@ -25,10 +25,13 @@
 Paddle.configure do |config|
   # Use :development or :sandbox for the Sandbox API
   # Or use :production for the Production API
   config.environment = :sandbox
   config.api_key = ENV["PADDLE_API_KEY"]
+
+  # Set the API version. Defaults to 1
+  config.version = 1
 end
 ```
 
 ### Products
 
@@ -181,10 +184,14 @@
 Paddle::Transaction.create(items: [ { price_id: "pri_abc123", quantity: 1 } ])
 
 # Retrieve a transaction
 Paddle::Transaction.retrieve(id: "txn_abc123")
 
+# Retrieve a transaction with extra information
+# extra can be either "address", "adjustment", "adjustments_totals", "business", "customer", "discount"
+Paddle::Transaction.retrieve(id: "txn_abc123", extra: "customer")
+
 # Update a transaction
 # https://developer.paddle.com/api-reference/transaction/update-transaction
 Paddle::Transaction.update(id: "txn_abc123", items: [ { price_id: "pri_abc123", quantity: 2 } ])
 
 # Preview a transaction
@@ -208,9 +215,13 @@
 Paddle::Subscription.list(status: "active")
 Paddle::Subscription.list(status: "canceled")
 
 # Retrieve a subscription
 Paddle::Subscription.retrieve(id: "sub_abc123")
+
+# Retrieve a subscription with extra information
+# extra can be either "next_transaction" or "recurring_transaction_details"
+Paddle::Subscription.retrieve(id: "sub_abc123", extra: "next_transaction")
 
 # Preview an update to a subscription
 # https://developer.paddle.com/api-reference/subscriptions/preview-subscription
 Paddle::Subscription.preview(id: "sub_abc123", items: [ { price_id: "pri_123abc", quantity: 2 } ])