Add Task queues section

Author: donnemartin

README.md

@@ -1422,3 +1422,9 @@ The user is not blocked and the job is processed in the background.  During this
 **RabbitMQ** is popular but requires you to adapt to the 'AMQP' protocol and manage your own nodes.
 
 **Amazon SQS**, is hosted but can have high latency and has the possibility of messages being delivered twice.
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+### Task queues
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+Tasks queues receive tasks and their related data, runs them, then delivers their results.  They can support scheduling and can be used to run computationally-intensive jobs in the background.
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+**Celery** has support for scheduling and primarily has python support.