Issue #194 introduce Opayo as the new name for the gateway

Author: judgej

README.md

@@ -1,6 +1,6 @@
 # Omnipay: Sage Pay
 
-**Sage Pay driver for the Omnipay PHP payment processing library**
+**Sage Pay/Opayo driver for the Omnipay PHP payment processing library**
 
 [![Unit Tests](https://github.com/thephpleague/omnipay-sagepay/actions/workflows/run-tests.yml/badge.svg)](https://github.com/thephpleague/omnipay-sagepay/actions/workflows/run-tests.yml)
 [![Latest Stable Version](https://poser.pugx.org/omnipay/sagepay/version.png)](https://packagist.org/packages/omnipay/sagepay)
@@ -14,6 +14,11 @@ This version supports PHP ^7.3 and PHP ^8.
 This is the `master` branch of Omnipay, handling Omnipay version `3.x`.
 For the `2.x` branch, please visit https://github.com/thephpleague/omnipay-sagepay/tree/2.x
 
+From version 4.1.1 the new Opayo URLs are used in place of the old Sage Pay URLs.
+These new URLs will be mandatory from March 2023, so you must upgrade by then.
+The upgrade 4.0 to 4.1.1 should be seamless; all classes remain in the
+`Omnipay\SagePay` namespace.
+
 Table of Contents
 =================
 
@@ -965,7 +970,7 @@ or not, so can be used multiple times.
 
 # Basket format
 
-Sagepay currently supports two different formats for sending cart/item information to them:  
+Sagepay currently supports two different formats for sending cart/item information to them:
  - [BasketXML](http://www.sagepay.co.uk/support/12/36/protocol-3-00-basket-xml)
  - [Basket](http://www.sagepay.co.uk/support/error-codes/3021-invalid-basket-format-invalid)
 
@@ -985,28 +990,28 @@ The Basket format can be used for Sage 50 Accounts Software Integration:
 > reconcile the transactions on your account within your financial software.
 > If you wish to link a transaction to a specific product record this can be done through the Basket field
   in the transaction registration post.
-> Please note the following integration is not currently available when using BasketXML fields. 
+> Please note the following integration is not currently available when using BasketXML fields.
 > In order for the download of transactions to affect a product record the first entry in a basket line needs
   to be the product code of the item within square brackets. For example:
-  
+
 ```
 4:[PR001]Pioneer NSDV99 DVD-Surround Sound System:1:424.68:74.32:499.00:499.00
 ```
 
 You can either prepend this onto the description or using `\Omnipay\SagePay\Extend\Item` you can use `setProductCode`
-which will take care of pre-pending `[]` for you. 
+which will take care of pre-pending `[]` for you.
 
 # Account Types
 
 Your Sage Pay account will use separate merchant accounts for difference transaction sources.
 The sources are specified by the `accountType` parameter, and take one of three values:
 
-* "E" Omnipay\SagePay\Message\AbstractRequest::ACCOUNT_TYPE_E (default)  
+* "E" Omnipay\SagePay\Message\AbstractRequest::ACCOUNT_TYPE_E (default)
   For ecommerce transactions, entered in your application by the end user.
-* "M" Omnipay\SagePay\Message\AbstractRequest::ACCOUNT_TYPE_M  
+* "M" Omnipay\SagePay\Message\AbstractRequest::ACCOUNT_TYPE_M
   MOTO transactions taken by telephone or postal forms or faxes, entered by an operator.
   The operator may ask for a CVV when taking a telephone order.
-* "C" Omnipay\SagePay\Message\AbstractRequest::ACCOUNT_TYPE_C  
+* "C" Omnipay\SagePay\Message\AbstractRequest::ACCOUNT_TYPE_C
   For repeat transactions, generated by the merchant site without any human intervention.
 
 The "M" MOTO and "C" account types will also disable any 3D-Secure validation that may
@@ -1048,5 +1053,5 @@ If you believe you have found a bug, please report it using the [GitHub issue tr
 or better yet, fork the library and submit a pull request.
 
 #References
-- [Sage pay tokens using token management](https://www.opayo.co.uk/file/1171/download-document/sagepaytokensystemprotocolandintegrationguidelinev3.0_0.pdf)
+- [Sage pay tokens using token management](https://www.opayo.co.uk/file/2501/download-document/Token_System_Integration_and_Protocol_Guidelines3.00.pdf)
 - [Other sage pay transaction types for Server method](https://developer-eu.elavon.com/docs/opayo-shared-api)