docs: Add user guide for pin a stream

templates/zerver/help/index.md

@@ -95,7 +95,7 @@ as a “**realm**”.
 * Preview a stream (not implemented)
 * [Unsubscribe from a stream](/help/unsubscribe-stream)
 * Change who can join a stream
-* Pin a stream
+* [Pin a stream](/help/pin-a-stream)
 * [Change the color of a stream](/help/change-stream-color)
 * Message a stream by email
 * Convert a group PM to a private stream (not implemented)

templates/zerver/help/pin-a-stream.md

@@ -0,0 +1,52 @@
+# Pinning a stream
+
+Pinning a stream will put that stream at the top of your streams sidebar.
+If you are subscribed to a lot of streams,
+pinning your favorite streams can be a good way to keep things organized.
+
+## How to pin a stream
+
+There are two easy ways to pin a stream:
+
+### Pinning a stream using the sidebar
+
+The quickest way to pin a stream is by using the
+**Pin stream ... to top** feature on the sidebar.
+
+1) On the sidebar, hover over the stream you want to pin 
+and press the arrow to the right of the stream name.
+
+![Arrow](/static/images/help/streams-arrow.png)
+
+2) A menu will pop up. Press **Pin stream ... to top**.
+
+![Sidebar menu](/static/images/help/streams-pin-sidebar.png)
+
+### Pinning a stream using the stream settings
+
+The other way to pin a stream is by ticking the 
+**Pin stream to top of left sidebar** box in the stream settings.
+
+1) Open your subscription settings by pressing 
+the gear at the top of the left sidebar.
+
+![Browse streams](/static/images/help/streams-1.png)
+
+2) Now select the stream you want to pin and tick 
+the box **Pin stream to top of left sidebar**.
+
+![Stream settings](/static/images/help/streams-pin-settings.png)
+
+### Result
+
+The stream you just pinned will now be at the top of your streams list:
+
+![Result](/static/images/help/streams-pin-result.png)
+
+## How to unpin a stream
+
+Unpinning a stream works the same way as pinning a stream. You can:
+- Press the arrow to the right of the stream you want to unpin 
+and select **Unpin stream ... from top**, or
+- Open your subscription settings, select the stream you want to unpin 
+and untick the box **Pin stream to top of left sidebar**