Extend JSON Schema for GeoJSONFeatures to support Recipe 0139.

[markpbaggett]

The way the current schema is now a Resource can only be an AnnotationBody, TextualBody, SpecificResource, or Choice. Recipe 0139 though has it also including a GeoJSON Feature:

          {
              "id": "https://iiif.io/api/cookbook/recipe/0139-geolocate-canvas-fragment/geoAnno.json",
              "type": "Annotation",
              "motivation": "tagging",
              "body": {
                "id": "https://iiif.io/api/cookbook/recipe/0139-geolocate-canvas-fragment/geo.json",
                "type": "Feature",
                "properties": {
                  "label": {
                    "en": [
                      "Targeted Map from Chesapeake and Ohio Canal Pamphlet"
                    ]
                  }
                },
                "geometry": {
                  "type": "Polygon",
                  "coordinates": [
                    [
                      [
                        -77.019853,
                        38.913101
                      ],
                      [
                        -77.110013,
                        38.843254
                      ],
                      [
                        -77.284698,
                        38.997574
                      ],
                      [
                        -77.188911,
                        39.062648
                      ]
                    ]
                  ]
                }
              },
              "target": "https://iiif.io/api/cookbook/recipe/0139-geolocate-canvas-fragment/canvas.json#xywh=920,3600,1510,3000"
            }