Clarify config order of Praefects in one place

Co-authored-by: Evan Read <eread@gitlab.com>

doc/administration/gitaly/praefect.md

@@ -20,6 +20,9 @@ Configure Gitaly Cluster using either:
 
 Smaller GitLab installations may need only [Gitaly itself](index.md).
 
+To upgrade a Gitaly Cluster, follow the documentation for
+[zero downtime upgrades](../../update/zero_downtime.md#gitaly-cluster).
+
 ## Requirements
 
 The minimum recommended configuration for a Gitaly Cluster requires:
@@ -376,8 +379,8 @@ configuration option is set. For more details, consult the PgBouncer documentati
 
 If there are multiple Praefect nodes:
 
-- Complete the following steps for **each** node.
-- Designate one node as the "deploy node", and configure it first.
+1. Designate one node as the deploy node, and configure it using the following steps.
+1. Complete the following steps for each additional node.
 
 To complete this section you need a [configured PostgreSQL server](#postgresql), including:
 
@@ -556,8 +559,6 @@ On the **Praefect** node:
    edit `/etc/gitlab/gitlab.rb`, remember to run `sudo gitlab-ctl reconfigure`
    again before trying the `sql-ping` command.
 
-**The steps above must be completed for each Praefect node!**
-
 #### Enabling TLS support
 
 > [Introduced](https://gitlab.com/gitlab-org/gitaly/-/issues/1698) in GitLab 13.2.