docs: Break up a long sentence in Apple auth instructions.

This also helps keep the actionable part short, by separating
the actionable instruction from the longer parenthetical
explaining what it's for.

docs/production/authentication-methods.md

@@ -603,13 +603,13 @@ domain for your server).
   and "Team ID" as `SOCIAL_AUTH_APPLE_TEAM` in `settings.py` file.
 
 1. In the Apple developer site, configure the domains your Zulip
-server uses when sending outgoing email notifications (this is
-required for your Zulip server to deliver emails to the many Apple
-users who use their privacy-protecting forwarding service). See the
-"Email Relay Service" subsection of [this page][apple-get-started] for
-more information.  See Zulip's [outgoing email
-documentation][outgoing-email] for details on what From addresses
-Zulip uses when sending outgoing emails.
+   server uses when sending outgoing email notifications.  (This is
+   required for your Zulip server to deliver emails to the many Apple
+   users who use their privacy-protecting forwarding service.)  See the
+   "Email Relay Service" subsection of [this page][apple-get-started]
+   for more information.  See Zulip's [outgoing email
+   documentation][outgoing-email] for details on what From addresses
+   Zulip uses when sending outgoing emails.
 
 [apple-create-services-id]: https://help.apple.com/developer-account/?lang=en#/dev1c0e25352
 [apple-developer]: https://developer.apple.com/account/resources/