Clarification on deployment configuration

[tonyf]

It would be helpful to have further documentation on deployment recommendations in a production setting.

For example:

• Should the parameter server / lighthouse server be colocated for performance? Is it necessary to have high speed interconnect between the lighthouse server and the worker nodes?
• Can a single lighthouse server be shared amongst multiple training jobs? If so, how are the instances/jobs distinguished from each other?
• What kind of minimum specs are recommended for the lighthouse / parameter servers? How does this relate to model size?