Update GCP SCTFE CI enviornment README

Author: roger2hk

deployment/live/gcp/ci/README.md

@@ -3,7 +3,7 @@
 ## Overview
 
 This config uses the [gcp/conformance](/deployment/modules/gcp/conformance) module to
-define a CI environment to run the SCTFE, backed by Trillian Tessera.
+define a CI environment to run the SCTFE on Cloud Run, backed by Trillian Tessera.
 
 At a high level, this environment consists of:
 - One Spanner instance with two databases:
@@ -13,6 +13,10 @@ At a high level, this environment consists of:
 - Secret Manager
 - Cloud Run
 
+### Automatic Deployment
+
+This GCP SCTFE conformance CI environment is designed to be deployed by the Cloud Build ([Terraform module](/deployment/modules/gcp/cloudbuild/), [Terragrunt configuration](/deployment/live/gcp/cloudbuild/prod/)).
+
 ### Manual Deployment
 
 First authenticate via `gcloud` as a principle with sufficient ACLs for