Add approve user doc (#421)

Author: heisbrot

public/docs-static/img/approval/netbird-authentication-settings-approval.png

@@ -155,6 +155,7 @@ export const docsNavigation = [
              isOpen: false,
              links: [
                  { title: 'Add Users to Your Network', href: '/how-to/add-users-to-your-network' },
+                 { title: 'Approve Users', href: '/how-to/approve-users' },
                  {
                      title: 'Provision Users & Groups',
                      href: '/how-to/idp-sync',

public/docs-static/img/approval/netbird-user-approval.png

@@ -0,0 +1,31 @@
+import {Note} from "@/components/mdx";
+
+# Approve users
+The user approval feature enhances security by requiring manual administrator approval before a user can join your NetBird organization via domain matching.
+
+## Require user approval
+Navigate to the Dashboard's `Settings` page and the `Authentication` tab and enable or disable `User Approval Required`.
+
+- **Enabled**: Require manual approval for new users joining via domain matching. Users will be blocked until approved. Learn how to approve or reject users in the section [below](#approve-or-reject-user).
+- **Disabled**: Manual approval for new users is not required. Users joining via domain matching will be automatically added to the organization.
+
+<p>
+    <img src="/docs-static/img/approval/netbird-authentication-settings-approval.png" alt="netbird-authentication-settings-approval" className="imagewrapper-big"/>
+</p>
+
+## Approve or reject user
+To approve a user, navigate to the [Users Page](https://app.netbird.io/team/users) and click the `Approve` or `Reject` button on the right side of the users table.
+
+<p>
+    <img src="/docs-static/img/approval/netbird-user-approval.png" alt="netbird-user-approval" className="imagewrapper-big"/>
+</p>
+
+## Get started
+<p float="center" >
+    <Button name="button" className="button-5" onClick={() => window.open("https://netbird.io/pricing")}>Use NetBird</Button>
+</p>
+
+- Make sure to [star us on GitHub](https://github.com/netbirdio/netbird)
+- Follow us [on X](https://x.com/netbird)
+- Join our [Slack Channel](/slack-url)
+- NetBird [latest release](https://github.com/netbirdio/netbird/releases) on GitHub