docs: add deployment docs to readme

readme.md

@@ -31,3 +31,34 @@ run a development server on [http://localhost:3000](http://localhost:3000):
 ```bash
 pnpm run dev
 ```
+
+## how to deploy
+
+- ask a sysadmin to create a new acdh-ch kubernetes project.
+- create a new namespace in that project via [rancher](https://rancher.acdh-dev.oeaw.ac.at), and set
+  the `KUBE_NAMESPACE` github variable as well as the
+  [`app_name`](./.github/workflows/build-deploy.yml#L36) to that namespace.
+- set the `PUBLIC_URL` github variable to the application's public url (e.g.
+  "https://my-app.acdh-ch-dev.oeaw.ac.at"), and set the `KUBE_INGRESS_BASE_DOMAIN` to the public
+  url's base domain (e.g. "acdh-ch-dev.oeaw.ac.at").
+- create a service issue in the acdh-ch [redmine](https://redmine.acdh.oeaw.ac.at) issue tracker,
+  and set the `SERVICE_ID` github variable to the issue number. this should match the
+  `NUXT_PUBLIC_REDMINE_ID` variable in your `.env.local` file.
+- ensure required build args (prefixed with `NUXT_PUBLIC_`) are referenced in both the
+  [`Dockerfle`](./Dockerfile), as well as the [validation](./.github/workflows/validate.yml) as
+  [deployment](./.github/workflows/build-deploy.yml) pipelines, and set as github variables.
+- ensure required runtime environment variables are referenced in the
+  [validation](./.github/workflows/validate.yml) and
+  [deployment](./.github/workflows/build-deploy.yml) pipelines, and set as github secrets. github
+  secrets need to be prefixed with `K8S_SECRET_` to be automatically copied to the runtime
+  environment. in case you need secrets in the docker build context, you can
+  [mount a secret in the Dockerfile](https://docs.docker.com/build/building/secrets/).
+- ensure both the github repository, as well as the
+  [package registry](https://github.com/orgs/acdh-oeaw/packages/container/my-app/settings) is set to
+  public.
+
+if everything is set up correctly, every git push to the `main` branch will create a new deployment
+if the validation pipeline passes.
+
+you can reference the [template repository](https://github.com/acdh-oeaw/template-app-nuxt) for a
+working setup.