anchor.diff:  The https://github.com/eclipse/microprofile-open-api/blob/master/api/src/main/java/org/eclipse/microprofile/openapi/OASModelReader.java[OASModelReader] interface allows application developers to bootstrap the OpenAPI model tree
   used by the processing framework.  To use it, simply create an implementation of
   this interface and register it using the `mp.openapi.model.reader` configuration
  -key, where the value is the qualified name of the reader.
  +key, where the value is the fully qualified name of the reader class.
   
   .Sample META-INF/microprofile-config.properties
   [code,property]
  
positive.code: `Accept` header.
  
  === Query parameters
  No query parameter are required for the `/openapi` endpoint.  However, one
  suggested but optional query parameter for vendors to support is `format`,
  where the value can be `json`, to facilitate the toggle between the default `yaml`
  format and `json` format.
  
  === Context root behaviour
  Vendors are required to ensure that the combination of each global https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#serverObject[server]
  
negative.code: === Static OpenAPI files
  
  Application developers may wish to include a pre-generated OpenAPI document that
  was written separately from the code (e.g. with an editor such as https://editor.swagger.io/[this]).
  
  Depending on the scenario, the document may be fully complete or partially complete.
  If a document is fully complete then the application developer will want to set the
  `mp.openapi.scan.disable` configuration property to `true`.  If a document is partially
  complete, then the application developer will need to augment the OpenAPI snippet
  with annotations, programming model, or via the filter.
  
  ==== Location and formats
  
  Vendors are required to fetch a single document with extension of `yml`, `yaml` or
  `json`, inside the application's `META-INF/openapi` folder.  If there is more than
  one document found that matches one of these extensions the behavior of which file
  is chosen is undefined (i.e. each vendor may implement their own logic), which means
  that application developers should only place a single document into that folder.
  
  === Programming model
  