User documentation updated for the PSI release

As a PSI operator, I want to simple easy follow instructions for how to command the SDP system so I can explore its functionality and use it to its full potential as part of system integration tests.

While the primary stakeholder here is a PSI operator, this will no doubt be just as valuable for developers and other stakeholders not familiar with the SDP operational system.

1. Given a well-defined deployment or staging environment, when I read the SDP PSI user documentation, I want to be able to find a clear set of instructions for deploying the SDP system including a description of how I know that this was successful. 
2. Given I have followed steps to deploy the SDP system, if the system fails to deploy correctly, I want a clear set of instructions I can use to try to understand this and use to raise an issue if the situation cannot be easily resolved.
3. Given a deployed and running SDP system, when I read the SDP PSI user documentation, I want a set of sets I can follow to 1) run and configure a receive workflow, 2) detect if this is running correctly 3) find out when the workflow has successfully ended/completed 4) how to obtain and test data received.
4. ...