YAML extends goes far beyond decoration - and must be explained appropriately.

Possible candidates to change / rewrite:

• https://documentation.magnolia-cms.com/display/DOCS/Reusing+configuration
  • add section for YAML extends
  • add section for YAML decoration
    • etc.
• https://documentation.magnolia-cms.com/display/DOCS/YAML
  • add a section listing and explaining the Magnolia specific directives