[Review] Request from 'dmajda' @ 'SUSE/machinery/data-model-docs-improvements'

Please review the following changes:
  * 62ec1f7 Data model docs: Add a "Root" header
  * cf77b10 Data model docs: Remove the "Scope Details" section
  * 97f1f40 Data model docs: Unify header capitalization
  * b854536 Data model docs: Add toplevel header