readme update

Author: pinzon

README.md

@@ -56,6 +56,7 @@ custom:
       # Enable this flag to run "docker ..." commands as sudo
       sudo: False
       compose_file: /home/localstack_compose.yml # optional to use docker compose instead of docker or localstack cli
+    image: localstack/localstack-pro # Docker image to use
   stages:
     local:
       ...
@@ -209,7 +210,7 @@ custom:
 ```
 
 ## Change Log
-* v1.4.0: Switch to LocalStack Pro image (`localstack/localstack-pro`), require `LOCALSTACK_AUTH_TOKEN`
+* v1.4.0: Use LocalStack Pro image (`localstack/localstack-pro`) by default, require `LOCALSTACK_AUTH_TOKEN`. Addition of `image` config var
 * v1.3.1: prevent the mounting of code if the Lambda uses an ECR Image
 * v1.3.0: add support for built-in Esbuild in Serverless Framework v4 #267
 * v1.2.1: Fix custom-resource bucket compatibility with serverless >3.39.0, continue improving support for `AWS_ENDPOINT_URL`