Deploy staging thumbnails along with staging API (#2455)

* Deploy staging thumbnails along with staging API

* Update ci/cd workflow docs

.github/workflows/ci_cd.yml

@@ -949,6 +949,22 @@ jobs:
           wait_time: 60 # check every minute
           max_time: 1800 # allow up to 30 minutes for a deployment
 
+      - name: Deploy staging thumbnails
+        uses: felixp8/dispatch-and-wait@v0.1.0
+        with:
+          owner: WordPress
+          repo: openverse-infrastructure
+          token: ${{ secrets.ACCESS_TOKEN }}
+          event_type: deploy_staging_api_thumbnails
+          client_payload: |
+            {
+              "actor": "${{ github.actor }}",
+              "tag": "${{ needs.get-image-tag.outputs.image_tag }}",
+              "run_name": "${{ steps.commit.outputs.commit_message }}"
+            }
+          wait_time: 60 # check every minute
+          max_time: 1800 # allow up to 30 minutes for a deployment
+
   ################
   # Notification #
   ################

documentation/meta/ci_cd/jobs/deployment.md

@@ -2,16 +2,17 @@
 
 ## `deploy-api`
 
-Triggers a separate workflow using `workflow_dispatch` that deploys the staging
-environment of the API service to AWS ECS. That workflow is given two inputs.
+Triggers two separate workflows using `workflow_dispatch` that deploys the
+staging environment of the API service and the thumbnails-specific API
+deployment to AWS ECS. That workflows are given two inputs.
 
 - the tag of the image that was published by the
   [`publish-images`](/meta/ci_cd/jobs/docker.md#publish-images) job, which is
   the output of the
   [`get-image-tag`](/meta/ci_cd/jobs/preparation.md#get-image-tag) job
 - the actor of the CI + CD workflow, for tagging them in Slack messages
 
-This deployment is only triggered if all the following conditions are met.
+The deployments are only triggered if all the following conditions are met.
 
 - the API codebase has changed
 - the [`publish-images`](/meta/ci_cd/jobs/docker.md#publish-images) job has