Add links in the documentation to facilitate navigation

[qligier]

Fixes #82

https://build.fhir.org/ig/qligier/ch-epr-mhealth/branches/ql_issue_82/index.html

[oliveregger]

we should the structure of ihe profiles as close as possible.

move transaction to actors and transcations and show the actors diagram (plantuml)

[oliveregger]

• distribute the resource to the different volume 1, volume 2 chapters
• introduce the chapters like the structure is on the underlying ihe profile

[qligier]

Done: https://build.fhir.org/ig/qligier/ch-epr-mhealth/branches/ql_issue_82/index.html