docs: Add user guide for signing out

templates/zerver/help/index.md

@@ -31,6 +31,7 @@ as a “**realm**”.
 - **[Message formatting](/help/message-formatting.md)**
 - **[Uploading and Sharing Files](/help/uploading_sharing_files)**
 - **[Other common questions](#other-common-questions)**
+- **[Signing out](signing-out.md)**
 - **[Terminology](#special-terms-used-with-zulip)**
 
 ---

templates/zerver/help/signing-out.md

@@ -0,0 +1,29 @@
+## Logging out of Zulip
+
+
+When you're done using Zulip, it's easy to log out.
+
+
+### Logging out on a browser:
+
+1. Click on the settings gear ( ![Gear](/static/images/help/cog.png) ) in the top right.  
+
+2. Click **Log Out**.
+
+![Desktop](/static/images/help/desktop_settings_menu_logout_highlighted.png)
+
+
+
+### Logging out of the iOS app:  
+
+1. Tap the menu icon ( ![Hamburger](/static/images/help/hamburger_icon.jpg) ) in the top left of your screen.
+
+2. Tap **Logout**.
+
+
+
+### Logging out of the Android app:  
+
+1. Tap the overflow menu ( ![Overflow](/static/images/help/overflow.png) ) in the top right of your screen.
+
+2. Tap **Logout**.