Move Grafana to a distinct step

Grafana is important for observing the behvaiour of Gitaly HA, and
should be prominent step with detailed information about how to monitor
the cluster. This first step moves the Grafana docs to its own section.

doc/administration/gitaly/praefect.md

@@ -44,6 +44,7 @@ package (highly recommended), follow the steps below:
 1. [Configuring the Praefect proxy/router](#praefect)
 1. [Configuring each Gitaly node](#gitaly) (once for each Gitaly node)
 1. [Updating the GitLab server configuration](#gitlab)
+1. [Configure Grafana](#grafana)
 
 ### Preparation
 
@@ -532,8 +533,6 @@ Particular attention should be shown to:
        ]
      }
    ]
-
-   grafana['disable_login_form'] = false
    ```
 
 1. Save the changes to `/etc/gitlab/gitlab.rb` and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure):
@@ -548,12 +547,6 @@ Particular attention should be shown to:
    gitlab-rake gitlab:gitaly:check
    ```
 
-1. Set the Grafana admin password. This command will prompt you to enter a new password:
-
-   ```shell
-   gitlab-ctl set-grafana-password
-   ```
-
 1. Update the **Repository storage** settings from **Admin Area > Settings >
    Repository > Repository storage** to make the newly configured Praefect
    cluster the storage location for new Git repositories.
@@ -566,11 +559,6 @@ Particular attention should be shown to:
    repository that viewed. If the project is created, and you can see the
    README file, it works!
 
-1. Inspect metrics by browsing to `/-/grafana` on your GitLab server.
-   Log in with `admin` / `GRAFANA_PASSWORD`. Go to 'Explore' and query
-   `gitlab_build_info` to verify that you are getting metrics from all your
-   machines.
-
 Congratulations! You have configured a highly available Praefect cluster.
 
 ### Failover
@@ -694,6 +682,49 @@ for example behind a load balancer, `failover_enabled` should be disabled. The r
 is no coordination that currently happens across different Praefect instances, so there could be a situation where
 two Praefect instances think two different Gitaly nodes are the primary.
 
+## Grafana
+
+Grafana is included with GitLab, and can be used to monitor your Praefect
+cluster. See [Grafana Dashboard
+Service](https://docs.gitlab.com/omnibus/settings/grafana.html)
+for detailed documentation.
+
+To get started quickly:
+
+1. SSH into the **GitLab** node and login as root:
+
+   ```shell
+   sudo -i
+   ```
+
+1. Enable the Grafana login form by editing `/etc/gitlab/gitlab.rb`.
+
+   ```ruby
+   grafana['disable_login_form'] = false
+   ```
+
+1. Save the changes to `/etc/gitlab/gitlab.rb` and [reconfigure
+   GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure):
+
+   ```shell
+   gitlab-ctl reconfigure
+   ```
+
+1. Set the Grafana admin password. This command will prompt you to enter a new
+   password:
+
+   ```shell
+   gitlab-ctl set-grafana-password
+   ```
+
+1. In your web browser, open `/-/grafana` (e.g.
+   `https://gitlab.example.com/-/grafana`) on your GitLab server.
+
+   Login using the password you set, and the username `admin`.
+
+1. Go to **Explore** and query `gitlab_build_info` to verify that you are
+   getting metrics from all your machines.
+
 ## Migrating existing repositories to Praefect
 
 If your GitLab instance already has repositories, these won't be migrated