help: Update "Archive a stream".

- Updates page to follow current help center documentation patterns.

help/add-or-remove-users-from-a-stream.md

@@ -130,7 +130,7 @@ subscribe the user.
 !!! tip ""
 
     You can also hover over a stream in the left sidebar, click on the
-    **ellipsis** (<i class="zulip-icon zulip-icon-ellipsis-v-solid"></i>), and
+    **ellipsis** (<i class="zulip-icon zulip-icon-more-vertical"></i>), and
     select **Stream settings** to access the **Subscribers** tab.
 
 {end_tabs}

help/archive-a-stream.md

@@ -13,24 +13,33 @@ messages and topics in the stream may or may not continue to work.
 In most cases, we recommend [renaming streams](/help/rename-a-stream) rather
 than archiving them.
 
-### Archive a stream
+## Archive a stream
 
 {start_tabs}
 
+{tab|desktop-web}
+
 {relative|stream|all}
 
 1. Select a stream.
 
-1. Click the <i class="fa fa-trash-o"></i> on the right.
+1. Click the **trash** <i class="fa fa-trash-o"></i> icon near the top right
+   corner of the stream settings panel.
 
 1. Approve by clicking **Confirm**.
 
+!!! tip ""
+
+    You can also hover over a stream in the left sidebar, click on the
+    **ellipsis** (<i class="zulip-icon zulip-icon-more-vertical"></i>), and
+    select **Stream settings** to access the **trash**
+    <i class="fa fa-trash-o"></i> icon.
+
 {end_tabs}
 
 !!! warn ""
 
-    Archiving a stream is currently irreversible, but we plan to add support
-    for unarchiving streams in the future.
+    Archiving a stream is currently irreversible via the UI.
 
 ## Related articles
 
@@ -38,3 +47,4 @@ than archiving them.
 * [Delete a message](/help/delete-a-message)
 * [Delete a topic](/help/delete-a-topic)
 * [Message retention policy](/help/message-retention-policy)
+* [Stream permissions](/help/stream-permissions)