docs: Add user guide for *Make a user an administrator* feature.

templates/zerver/help/deactivate-account.md

@@ -34,7 +34,7 @@ Zulip realm administrators can choose to reactivate a user's deactivated account
 
 3. Upon clicking **Administration**, your view will be replaced with the **Administration** page. Click the **Deactivated Users** tab at the top of the panel; it turns gray upon hover.
 
-    ![Administration](/static/images/help/admin-panel.png)
+    ![Administration](/static/images/help/admin-panel-deactivated-users.png)
 
 4. In the **Deactivated users** section, click the orange **Reactivate** button to the right of the user account that you want to reactivate.
 

templates/zerver/help/index.md

@@ -142,7 +142,7 @@ as a “**realm**”.
 ## Users & Bots
 * Deactivate or reactivate a user
 * Deactivate or reactivate a bot
-* Make a user an administrator
+* [Make a user an administrator](/help/make-a-user-an-administrator)
 * Change a user's name
 * View the list of installed bots
 

templates/zerver/help/make-a-user-an-administrator.md

@@ -0,0 +1,44 @@
+# Make a user an administrator
+
+> With great power comes great responsibility.
+
+By default, everyone in a realm is a user; this limits them from modifying
+realm-wide settings, such as changing the organization name, activating or
+deactivating users, deleting streams, etc. Zulip realm administrators can
+give a user administrative rights. To do so, follow the steps below:
+
+1. Click the (![cog](/static/images/help/cog.png)) in the upper right corner
+of the right sidebar.
+
+2. Select **Administration** from the dropdown menu.
+
+    ![admin](/static/images/help/admin.png)
+
+3. Upon clicking **Administration**, your view will be replaced with the
+**Administration** page. Click on **Users** in the tabs list.
+
+    ![admin panel](/static/images/help/admin-panel-generic.png)
+
+4. In the **Users** section, you will be presented with various settings
+for your users. Click on **Make admin** for the user(s) that you wish to
+make an administrator.
+
+    ![make admin](/static/images/help/make-admin.png)
+
+After clicking the **Make admin** button, the selected user's browser will
+reload and the user will gain administrative privileges immediately.
+
+## Revoke administrative rights from a user
+
+Administrators can also revoke the administrative rights given to a user.
+In the **Users** tab of the **Administration** page, click on the **Remove
+admin** button.
+
+  ![remove admin](/static/images/help/remove-admin.png)
+
+The selected user's browser will reload automatically, and the user will no
+longer have access to the administration page.
+
+#### Note:
+* A user given administrative privileges can revoke it him/herself.
+* There must be at least one administrator in a realm.