fixed ObservationTreatment link

Author: Guy Davenport

Specification/BrAPI-Schema/BrAPI-Phenotyping/ObservationUnit.json

@@ -93,7 +93,7 @@
                     "relationshipType": "one-to-many",
                     "referencedAttribute": "observationUnit",
                     "items": {
-                        "$ref": "../BrAPI-Phenotyping/ObservationUnit.json#/$defs/Treatment",
+                        "$ref": "../BrAPI-Phenotyping/ObservationUnit.json#/$defs/ObservationTreatment",
                         "description": "Treatments"
                     },
                     "title": "Treatments",