help: Add “Configure how links open” page.

- Documents "Open links with in-app browser" option.

help/configure-how-links-open.md

@@ -0,0 +1,22 @@
+# Configure how links open
+
+You can configure whether website links will open directly in the Zulip app, or
+in your device's default browser.
+
+## Configure whether to open links within the app
+
+{start_tabs}
+
+{tab|mobile}
+
+{!mobile-profile-menu.md!}
+
+1. Tap **Settings**.
+
+1. Toggle **Open links with in-app browser**.
+
+{end_tabs}
+
+## Related articles
+
+* [Link to a message or conversation](/help/link-to-a-message-or-conversation)

help/include/sidebar_index.md

@@ -86,6 +86,7 @@
 * [View your mentions](/help/view-your-mentions)
 * [Star a message](/help/star-a-message)
 * [View and browse images](/help/view-and-browse-images)
+* [Configure how links open](/help/configure-how-links-open)
 * [View messages sent by a user](/help/view-messages-sent-by-a-user)
 * [Link to a message or conversation](/help/link-to-a-message-or-conversation)
 * [Searching for messages](/help/search-for-messages)