Move admin template to admin/users.html

- Created templates/admin/ directory
- Moved admin_users.html to admin/users.html
- Updated render_template path in web.py

vidai/web.py

@@ -511,7 +511,7 @@ def admin():
     from .database import get_all_users
     users = get_all_users()
     user = get_current_user_session()
-    return render_template('admin.html', users=users, user=user, active_page='admin')
+    return render_template('admin/users.html', users=users, user=user, active_page='admin')
 
 @app.route('/admin/users/create', methods=['POST'])
 @admin_required