Document different possible building block configurations and use case examples

[j08lue]

Based on feedback from Q2 demo, we should document the different possible building block configurations (Resource Discovery + Data Access)

1. pycsw + eoAPI + Stacture
2. pycsw only (+ Stacture)
3. eoAPI only (+ Stacture)

and use cases for building block users.

Perhaps as the core example being how Terrabyte will use the building blocks.

[j08lue]

This task will roll over to the next quarter, pending clarification on

• Formulate a joint strategy for eoAPI and Stacture data-access#108

[j08lue]

Outdated due to deprecation of Stacture. Will follow up elsewhere.