docs(nav): add admin manual to sidebar

Updates the Astro configuration to include the "Managing Your Admin Account" manual in the Web Dashboard's sidebar navigation, making it visible on the documentation site.

Author: fulleni

astro.config.mjs

@@ -120,6 +120,7 @@ export default defineConfig({
 							items: [
 								{ label: 'Managing Content', link: '/web-dashboard/manuals/managing-content' },
 								{ label: 'Configuring the Mobile App', link: '/web-dashboard/manuals/configuring-the-app' },
+								{ label: 'Managing Your Admin Account', link: '/web-dashboard/manuals/managing-admin-account' },
 							],
 						},
 						{ label: 'Deployment', link: '/web-dashboard/deployment' },