Merge branch 'update-installation' into 'master'

Update installation

See merge request gitlab-com/www-gitlab-com!9132

source/installation/_platform.html.haml

@@ -36,10 +36,20 @@
 %h4
   3. Browse to the hostname and login
 :markdown
-  On your first visit, you'll be redirected to a password reset screen. Provide the password for the initial administrator account
-  and you will be redirected back to the login screen. Use the default account's username `root` to login.
+  On your first visit, you'll be redirected to a password reset screen. Provide the password for the initial administrator account and you will be redirected back to the login screen. Use the default account's username `root` to login.
   See our [documentation for detailed instructions on installing and configuration](https://docs.gitlab.com/omnibus/README.html#installation-and-configuration-using-omnibus-package).
+%h4
+  4. Set up your communication preferences
+%p
+  Visit our
+  %a{ href:"https://page.gitlab.com/SubscriptionCenter.html" }email subscription preference center
+  to let us know when to communicate with you. We have an explicit email opt-in policy so you have complete control over what and how often we send you emails. 
+%p
+  Twice a month, we send out the GitLab news you need to know, including new features, integrations, docs, and behind the scenes stories from our dev teams. For critical security updates related to bugs and system performance, sign up for our dedicated security newsletter.
+:markdown
+  IMPORTANT NOTE: If you do not opt-in to the security newsletter, you will not receive security alerts.
+  {: .alert .alert-warning}
 .display-extra-links
   %ul