Update readme for activejob EBS worker (#148)

Author: alextwoods

README.md

@@ -471,9 +471,15 @@ require_relative 'config/environment' # load rails
 ### Elastic Beanstalk workers: processing activejobs using worker environments
 
 Another option for processing jobs without managing the worker process is hosting the application in a scalable
-[Elastic Beanstalk worker environment](https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-tiers.html).
-This SDK includes Rack middleware that can be added conditionally and which will process requests from the
-SQS Daemon provided with each worker instance. The middleware will forward each request and parameters to their appropriate jobs.
+[Elastic Beanstalk worker environment](https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-tiers.html).  
+[Configure the worker](https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-tiers.html#using-features-managing-env-tiers-worker-settings) 
+to read from the correct SQS queue that you want to process jobs from and set the 
+```AWS_PROCESS_BEANSTALK_WORKER_REQUESTS``` environment variable to `true` in the worker environment configuration.
+Note that this will NOT start the poller.  Instead the
+[SQS Daemon](https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-tiers.html#worker-daemon)
+running on the worker sends messages as a POST request to `http://localhost/`. The middleware will forward each 
+request and parameters to their appropriate jobs. The middleware will only process requests from the SQS daemon 
+and will pass on others and so will not interfere with other routes in your application.
 
 To add the middleware on application startup, set the ```AWS_PROCESS_BEANSTALK_WORKER_REQUESTS``` environment variable to true
 in the worker environment configuration.