Merge branch 'docs-kubernetes-jupyter-app-update' into 'master'

Docs: clarify that Ingress is a prerequisite for JupyterHub

See merge request gitlab-org/gitlab-ee!10019

doc/user/project/clusters/index.md

@@ -361,7 +361,7 @@ by GitLab before installing any of the applications.
 | [Cert Manager](http://docs.cert-manager.io/en/latest/) | 11.6+ | Cert Manager is a native Kubernetes certificate management controller that helps with issuing certificates. Installing Cert Manager on your cluster will issue a certificate by [Let's Encrypt](https://letsencrypt.org/) and ensure that certificates are valid and up-to-date. | [stable/cert-manager](https://github.com/helm/charts/tree/master/stable/cert-manager) |
 | [Prometheus](https://prometheus.io/docs/introduction/overview/) | 10.4+ | Prometheus is an open-source monitoring and alerting system useful to supervise your deployed applications. | [stable/prometheus](https://github.com/helm/charts/tree/master/stable/prometheus) |
 | [GitLab Runner](https://docs.gitlab.com/runner/) | 10.6+ | GitLab Runner is the open source project that is used to run your jobs and send the results back to GitLab. It is used in conjunction with [GitLab CI/CD](https://about.gitlab.com/features/gitlab-ci-cd/), the open-source continuous integration service included with GitLab that coordinates the jobs. When installing the GitLab Runner via the applications, it will run in **privileged mode** by default. Make sure you read the [security implications](#security-implications) before doing so. | [runner/gitlab-runner](https://gitlab.com/charts/gitlab-runner) |
-| [JupyterHub](http://jupyter.org/) | 11.0+ | [JupyterHub](https://jupyterhub.readthedocs.io/en/stable/) is a multi-user service for managing notebooks across a team. [Jupyter Notebooks](https://jupyter-notebook.readthedocs.io/en/latest/) provide a web-based interactive programming environment used for data analysis, visualization, and machine learning. We use a [custom Jupyter image](https://gitlab.com/gitlab-org/jupyterhub-user-image/blob/master/Dockerfile) that installs additional useful packages on top of the base Jupyter. Authentication will be enabled only for [project members](../members/index.md) with [Developer or higher](../../permissions.md) access to the project. You will also see ready-to-use DevOps Runbooks built with Nurtch's [Rubix library](https://github.com/amit1rrr/rubix). More information on creating executable runbooks can be found in [our Nurtch documentation](runbooks/index.md#nurtch-executable-runbooks). | [jupyter/jupyterhub](https://jupyterhub.github.io/helm-chart/) |
+| [JupyterHub](http://jupyter.org/) | 11.0+ | [JupyterHub](https://jupyterhub.readthedocs.io/en/stable/) is a multi-user service for managing notebooks across a team. [Jupyter Notebooks](https://jupyter-notebook.readthedocs.io/en/latest/) provide a web-based interactive programming environment used for data analysis, visualization, and machine learning. We use a [custom Jupyter image](https://gitlab.com/gitlab-org/jupyterhub-user-image/blob/master/Dockerfile) that installs additional useful packages on top of the base Jupyter. Authentication will be enabled only for [project members](../members/index.md) with [Developer or higher](../../permissions.md) access to the project. You will also see ready-to-use DevOps Runbooks built with Nurtch's [Rubix library](https://github.com/amit1rrr/rubix). More information on creating executable runbooks can be found in [our Nurtch documentation](runbooks/index.md#nurtch-executable-runbooks). Note that Ingress must be installed and have an IP address assigned before JupyterHub can be installed. | [jupyter/jupyterhub](https://jupyterhub.github.io/helm-chart/) |
 | [Knative](https://cloud.google.com/knative) | 11.5+ | Knative provides a platform to create, deploy, and manage serverless workloads from a Kubernetes cluster. It is used in conjunction with, and includes [Istio](https://istio.io) to provide an external IP address for all programs hosted by Knative. You will be prompted to enter a wildcard domain where your applications will be exposed. Configure your DNS server to use the external IP address for that domain. For any application created and installed, they will be accessible as `<program_name>.<kubernetes_namespace>.<domain_name>`. This will require your kubernetes cluster to have [RBAC enabled](#role-based-access-control-rbac). | [knative/knative](https://storage.googleapis.com/triggermesh-charts)
 
 With the exception of Knative, the applications will be installed in a dedicated