Docs: deployment process to Azure Web App (#2128)

Author: angela-tran

docs/deployment/README.md

@@ -10,11 +10,8 @@ The Django application gets built into a [Docker image][dockerfile] with [NGINX]
 The application is deployed to an [Azure Web App Container][az-webapp] using three separate environments for `dev`, `test`,
 and `prod`.
 
-A [GitHub Action][gh-actions] per environment is responsible for building that branch's image and pushing to [GitHub Container
-Registry (GHCR)][ghcr].
-
-GitHub POSTs a [webhook][gh-webhooks] to the Azure Web App when an [image is published to GHCR][gh-webhook-event], telling
-Azure to restart the app and pull the latest image.
+The [Deploy](deploy-workflow) workflow is responsible for building that branch's image and pushing to [GitHub Container
+Registry (GHCR)][ghcr]. It also deploys to the Azure Web App, telling Azure to restart the app and pull the latest image.
 
 You can view what Git commit is deployed for a given environment by visitng the URL path `/static/sha.txt`.
 
@@ -34,9 +31,7 @@ Docker images for each of the deploy branches are available from GitHub Containe
 [oet]: https://techblog.cdt.ca.gov/2020/06/cdt-taking-the-lead-in-digital-transformation/
 [app-service-containers]: https://docs.microsoft.com/en-us/azure/app-service/configure-custom-container
 [app-service]: https://docs.microsoft.com/en-us/azure/app-service/overview
+[deploy-workflow]: https://github.com/cal-itp/benefits/blob/dev/.github/workflows/deploy.yml
 [dockerfile]: https://github.com/cal-itp/benefits/blob/dev/Dockerfile
 [az-webapp]: https://azure.microsoft.com/en-us/services/app-service/containers/
-[gh-actions]: https://docs.github.com/en/actions
-[gh-webhook-event]: https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#package
-[gh-webhooks]: https://docs.github.com/en/github-ae@latest/developers/webhooks-and-events/webhooks
 [ghcr]: https://github.com/features/packages