Merge branch 'docs-improvement' into 'master'

Docs improvement (GONRG-1035)

See merge request !29

provider/register-gcp/README.md

@@ -33,9 +33,12 @@ In order to run the service locally or remotely, you will need to have the follo
 | `STORAGE_API` | ex `https://os-storage-dot-opendes.appspot.com/api/storage/v2` | Storage API endpoint | no | output of infrastructure deployment |
 | `RECORDS_CHANGE_PUBSUB_ENDPOINT` | ex `https://os-notification-dot-opendes.appspot.com/push-handlers/records-changed` | Notification API endpoint 'records-changed'  | no | output of infrastructure deployment |
 | `GOOGLE_CLOUD_PROJECT` | ex `opendes` | Google Cloud Project Id | no | output of infrastructure deployment |
-| `SUBSCRIBER_SECRET` | `********` | - | yes | output of infrastructure deployment |
-| `SUBSCRIBER_PRIVATE_KEY_ID` | `********` | - | yes | output of infrastructure deployment |
+| `SUBSCRIBER_SECRET` | ex`7a786376626e` | HMAC_SECRET from notification int tests in HEX , pattern(^[a-zA-Z0-9]{8,30}+$)  | yes | output of infrastructure deployment |
+| `SUBSCRIBER_PRIVATE_KEY_ID` | `********` | Private key id of DE_OPS_TESTER from notification int tests| yes | output of infrastructure deployment |
 | `INTEGRATION_TEST_AUDIENCES` | ex `*****.apps.googleusercontent.com` | Client ID for getting access to cloud resources | yes | https://console.cloud.google.com/apis/credentials |
+| `SERVICE_IDENTITY` | ex `osdu-gcp-sa` |  Service account identity "**osdu-gcp-sa**@iam.gserviceaccount.com" | yes | https://console.cloud.google.com/apis/credentials |
+| `ENVIRONMENT` | ex `dev` |  Service environment config | no | - |
+| `GCLOUD_REGION` | ex `us-central1` |  cloud region | no | - |
 
 **System Environment required to run service**