Add link to v1 branch

Author: bboure

README.md

@@ -91,7 +91,7 @@ appSync:
 
 # Upgrading from v1
 
-To upgrade form v1 of this plugin, [follow this guide](doc/upgrading-from-v1.md)
+To upgrade form [v1](https://github.com/sid88in/serverless-appsync-plugin/tree/v1) of this plugin, [follow this guide](doc/upgrading-from-v1.md)
 
 # Contributing
 

doc/upgrading-from-v1.md

@@ -4,6 +4,8 @@
 
 This page will guide you through the process of migrating existing stacks to the newer version.
 
+The v1 is still available on the [v1](https://github.com/sid88in/serverless-appsync-plugin/tree/v1) branch
+
 ## Breaking changes and dropped features
 
 There are a few breaking changes that you need to be aware of.