try to add one more bit - approval date

Signed-off-by: Brent Zundel <brent.zundel@gmail.com>

docs/openapi/components/schemas/credentials/USDAPermitToImportCredential.yml

@@ -100,13 +100,21 @@ properties:
         $linkedData:
           term: intendedUse
           '@id': https://vocabulary.uncefact.org/intendedUse
+      approvalDate:
+        title: Signature Date
+        description: Date when the application was approved.
+        type: string
+        $linkedData:
+          term: approvalDate
+          '@id': https://vocabulary.uncefact.org/issueDateTime
     additionalProperties: false
     required:
       - applicationNumber		
       - permitNumber
       - applicant
       - permittee	
       - intendedUse
+      - approvalDate
 additionalProperties: false
 required:
   - '@context'
@@ -339,6 +347,7 @@ example: |-
           "leiCode": "54321351219389121979"
         }
       },
-      "intendedUse": "fruits and vegetables"
+      "intendedUse": "fruits and vegetables",
+      "approvalDate": "2021-02-16"
     }
   }