Running Multiple BlueAPIs in Parallel

On a beamline, is it useful to be able to deploy multiple instances of BlueAPI simultaneously, potentially using different versions.

For example, if BlueAPI cannot be updated (eg. during a run) but a newer feature is required, running both simultaneously is preferable to having down-time while upgrading.

Also, in general, not having to remove your stable deployment when upgrading is less stressful.

## Acceptance Criteria
- Documentation exists stating whether running multiple BlueAPIs in parrallel is supported, and if so it how to do it