feat: add vaccinated field to Pet schema (#6)

* feat: add vaccinated field to Pet schema

* chore: add changeset

Author: omermorad

.contractual/changesets/add-vaccinated-field.md

@@ -0,0 +1,7 @@
+---
+"petstore": minor
+---
+
+## petstore
+
+- **[minor]** add optional vaccinated field to track pet vaccination status

specs/petstore.openapi.yaml

@@ -144,6 +144,9 @@ components:
           type: string
           pattern: '^[0-9]{15}$'
           description: 15-digit microchip ID (optional)
+        vaccinated:
+          type: boolean
+          description: Whether the pet is vaccinated (optional)
         status:
           type: string
           enum: