Update rest-api-spec

Co-authored-by: delvedor <[email protected]>

Author: github-actions[bot]

specification/_json_spec/ml.start_trained_model_deployment.json

@@ -33,7 +33,7 @@
       },
       "number_of_allocations": {
         "type": "int",
-        "description": "The number of model allocations on each node where the model is deployed.",
+        "description": "The total number of allocations this model is assigned across machine learning nodes.",
         "required": false,
         "default": 1
       },