feat(specs): add size to predict segment response (#1434)

Co-authored-by: Clément Vannicatte <vannicattec@gmail.com>

Author: bengreenbank

specs/predict/responses/Segment.yml

@@ -68,6 +68,7 @@ segment:
     - segmentID
     - name
     - conditions
+    - size
     - segmentStatus
     - type
     - lastUpdatedAt
@@ -78,6 +79,8 @@ segment:
       $ref: '#/segmentName'
     conditions:
       $ref: '#/segmentParentConditions'
+    size:
+      $ref: '#/segmentSize'
     segmentStatus:
       $ref: '#/segmentStatus'
     type:
@@ -110,6 +113,11 @@ segmentName:
   type: string
   description: The name of the segment.
 
+segmentSize:
+  type: number
+  format: int64
+  description: The approximate number of users that matched the segment conditions when it was created, last updated, or when model inference last ran.
+
 updatedAt:
   type: string
   description: The date and time at which the segment was updated (RFC3339).