docs: Extract help doc for wildcard mention policy.

This commit moves the wildcard mentions documentation to a top-level page.

Edited by tabbott to deduplicate with the existing docs, and add cross-links.

templates/zerver/help/include/sidebar_index.md

@@ -133,6 +133,7 @@
 * [Weekly digest emails](/help/digest-emails)
 * [Disable welcome emails](/help/disable-welcome-emails)
 * [Configure notification bot](/help/configure-notification-bot)
+* [Restrict wildcard mentions](/help/restrict-wildcard-mentions)
 * [Require topics in stream messages](/help/require-topics)
 * [Add custom emoji](/help/add-custom-emoji)
 * [Configure authentication methods](/help/configure-authentication-methods)

templates/zerver/help/mention-a-user-or-group.md

@@ -57,30 +57,6 @@ wildcard mentions, either
 [globally](/help/pm-mention-alert-notifications) or for [individual
 streams](/help/stream-notifications).
 
-### Restrictions on wildcard mentions
+## Related articles
 
-Organization administrators can set a policy for which users are
-allowed to use wildcard mentions.
-
-Zulip allows anyone to use wildcard mentions in streams with at most
-15 subscribers.
-
-Organizations administrators can configure a policy for which classes
-of users are allowed to use wildcard mentions in streams with more
-than 15 subscribers.  The default allows only organization
-administrators to use wildcard mentions in large streams.
-
-Users permitted to use wildcard mentions by the organization's policy
-are warned that wildcard mentions result in everyone receiving email
-and mobile push notifications.
-
-{start_tabs}
-
-{settings_tab|organization-permissions}
-
-2. Under **Organization permissions**, configure
-   **Who can use wildcard mentions in large streams**.
-
-{!save-changes.md!}
-
-{end_tabs}
+* [Restrict wildcard mentions](/help/restrict-wildcard-mentions)

templates/zerver/help/moderating-open-organizations.md

@@ -24,7 +24,7 @@ Zulip has many features designed to simplify moderation:
   new users can take disruptive actions.
 * [Restrict email visibility](/help/restrict-visibility-of-email-addresses)
   to reduce the likelihood of off-platform spam.
-* [Restrict wildcard mentions](/help/mention-a-user-or-group#restrictions-on-wildcard-mentions)
+* [Restrict wildcard mentions](/help/restrict-wildcard-mentions)
   so only moderators can mention everyone in your organization.
 
 ## Response

templates/zerver/help/pm-mention-alert-notifications.md

@@ -35,8 +35,11 @@ can toggle whether you receive notifications for wildcard mentions:
 {end_tabs}
 
 Additionally, you can override this configuration for individual
-streams in your [Stream settings](/help/stream-notifications).
+streams in your [Stream settings](/help/stream-notifications), and
+administrators can [restrict use of wildcard
+mentions](/help/restrict-wildcard-mentions) in large streams.
 
 ## Related articles
 
 * [Add an alert word](/help/add-an-alert-word)
+* [Restrict wildcard mentions](/help/restrict-wildcard-mentions)

templates/zerver/help/restrict-wildcard-mentions.md

@@ -0,0 +1,28 @@
+# Restrict wildcard mentions
+
+{!admin-only.md!}
+
+Organization administrators can set a policy for which users are
+allowed to use [wildcard
+mentions](/help/pm-mention-alert-notifications#wildcard-mentions) in
+large streams (defined for this purpose as streams with more than 15
+subscribers).
+
+Zulip allows anyone to use wildcard mentions in streams with at most
+15 subscribers. The default allows only organization administrators to
+use wildcard mentions in large streams.
+
+Users permitted to use wildcard mentions by the organization's policy
+are warned that wildcard mentions will result in all subscribers
+receiving email and mobile push notifications.
+
+{start_tabs}
+
+{settings_tab|organization-permissions}
+
+2. Under **Organization permissions**, configure
+   **Who can use wildcard mentions in large streams**.
+
+{!save-changes.md!}
+
+{end_tabs}