Document release process for workers-shared's asset-worker and router-worker (#8040)

Author: WillTaylorDev

packages/workers-shared/README.md

@@ -2,6 +2,10 @@
 
 This is a package that is used at Cloudflare to power some internal features of [Cloudflare Workers](https://developers.cloudflare.com/workers/), as well as their open-source equivalents here in workers-sdk and Wrangler.
 
+> [!NOTE]
+> Since code in this package is used by the Workers infrastructure, it is important that PRs are given careful review with regards to how they could cause a failure in production.
+> Ideally, there should be comprehensive tests for changes being made to give extra confidence about the behavior.
+
 ## `asset-worker`
 
 The Asset Worker.
@@ -14,6 +18,15 @@ The Router Worker.
 
 For more details please refer to the dedicated README file.
 
-> [!NOTE]
-> Since code in this package is used by the Workers infrastructure, it is important that PRs are given careful review with regards to how they could cause a failure in production.
-> Ideally, there should be comprehensive tests for changes being made to give extra confidence about the behavior.
+## `Worker Deployment`
+
+Router-worker and asset-worker are both version uploaded through the run `deploy` target in this package, which uploads a new version of these Workers.
+
+There are two ways that the `deploy` script target can be invoked:
+
+- The `changesets` workflow will execute whenever there is a release of `@cloudflare/workers-shared`
+- If a change is needed prior to a workers-shared release, it can be done manually, via the `workers-shared-deploy-production` workflow. This workflow will upload new vesions of asset-worker and router-worker based on the code in the `main` branch. (Note, a duplicate version may be uploaded on the next workers-shared release, if there is an associated changeset)
+
+The pnpm `deploy` script should not be run manually.
+
+Once new versions are uploaded (through either the manual workflow, or the changesets workflow), they can be safely deployed and monitored using Gradual Deployments through Health Mediated Deployments.