Document our FHIR templates

[euanmillar]

It is not easy for implementers to understand our approach to FHIR and it is not easy for our Civil Registration community to understand the relevance of a Health standard to the Civil Registration context.

Our customisations of FHIR are not exhaustively documented here: https://documentation.opencrvs.org/technology/standards/fhir-documents

The Jembi hosted OpenCRVS FHIR templates are not up to date and are not owned by the organisation.

The FHIR specification URLs in the code do not link to any explanation of the possible parameters and use cases for each of the customisations.

We need to create documentation pages and update our standard appropriately.