docs: add instructions for obtaining admin token in API docs

16. `docs/api.md

@@ -11,6 +11,30 @@ ### POST /api/logout
 - **Description**: Logout the user and revoke the token.
 - **Response**: JSON object with a success message.
 
+### Obtaining an Admin Token
+- **Description**: To obtain a token for an admin user, follow these steps:
+  1. **Ensure the Admin User Exists**: Make sure there is an admin user in the database. If not, create one using the following command:
+     ```bash
+     php artisan tinker
+     $user = new App\Models\User;
+     $user->name = 'Admin User';
+     $user->email = 'admin@example.com';
+     $user->password = bcrypt('password');
+     $user->role = 'admin';
+     $user->save();
+     exit
+     ```
+  2. **Authenticate the Admin User**: Use the `/api/login` endpoint to authenticate the admin user and obtain the token. Send a POST request with the admin user's credentials:
+     ```bash
+     curl -X POST http://your-app-url/api/login -H "Content-Type: application/json" -d '{"email":"admin@example.com","password":"password"}'
+     ```
+  3. **Response**: The response will include a JSON object with the generated token:
+     ```json
+     {
+       "token": "your-generated-token"
+     }
+     ```
+
 ## Admin Management
 
 ### GET /api/admin/users