Use RabbitMQ 4.0 in documentation

Author: acogoluegnes

README.md

@@ -1,6 +1,6 @@
 ## RabbitMQ Performance Testing Tool
 
-[![Test against RabbitMQ 3.12 stable](https://github.com/rabbitmq/rabbitmq-perf-test/actions/workflows/test.yml/badge.svg)](https://github.com/rabbitmq/rabbitmq-perf-test/actions/workflows/test.yml)
+[![Test against RabbitMQ stable](https://github.com/rabbitmq/rabbitmq-perf-test/actions/workflows/test.yml/badge.svg)](https://github.com/rabbitmq/rabbitmq-perf-test/actions/workflows/test.yml)
 
 This repository contains source code of the RabbitMQ Performance Testing Tool.
 The client is maintained by the [RabbitMQ team at Broadcom](https://github.com/rabbitmq/).
@@ -93,7 +93,7 @@ You need a local running RabbitMQ instance.
 
 Start a RabbitMQ container:
 
-    docker run -it --rm --name rabbitmq -p 5672:5672 rabbitmq:3.12
+    docker run -it --rm --name rabbitmq -p 5672:5672 rabbitmq:4.0
 
 Run the test suite:
 

src/docs/asciidoc/installation.adoc

@@ -40,6 +40,6 @@ To run the RabbitMQ broker within Docker, and run PerfTest against it, run the
 following commands:
 
  docker network create perf-test
- docker run -it --rm --network perf-test --name rabbitmq -p 15672:15672 rabbitmq:3.12-management
+ docker run -it --rm --network perf-test --name rabbitmq -p 15672:15672 rabbitmq:4.0-management
  docker run -it --rm --network perf-test pivotalrabbitmq/perf-test:latest --uri amqp://rabbitmq