📝 Update README

Author: marcode24

README.md

@@ -70,7 +70,7 @@ npm run test 'year'/'folder-name'/solution.test.js
 | 18  | [Conjuntos](https://retosdeprogramacion.com/roadmap/)                                        |     🟢     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/18-conjuntos/index.js)  <br /> [![TypeScript](https://img.shields.io/badge/-TypeScript-3178C6?style=flat&logo=typescript&logoColor=white)](./2024/17-iteraciones/solution.ts) |
 | 19  | [Enumeraciones](https://retosdeprogramacion.com/roadmap/)                                    |     🟡     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/19-enumeraciones/index.js)  <br /> [![TypeScript](https://img.shields.io/badge/-TypeScript-3178C6?style=flat&logo=typescript&logoColor=white)](./2024/19-enumeraciones/solution.ts) |
 | 20  | [Peticiones HTTP](https://retosdeprogramacion.com/roadmap/)                                  |     🔴     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/20-peticiones-http/index.js) <br /> [![TypeScript](https://img.shields.io/badge/-TypeScript-3178C6?style=flat&logo=typescript&logoColor=white)](./2024/20-peticiones-http/solution.ts) |
-| 21  | [Callbacks](https://retosdeprogramacion.com/roadmap/)                                        |     🟡     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/21-callbacks/index.js) |
+| 21  | [Callbacks](https://retosdeprogramacion.com/roadmap/)                                        |     🟡     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/21-callbacks/index.js) <br /> [![TypeScript](https://img.shields.io/badge/-TypeScript-3178C6?style=flat&logo=typescript&logoColor=white)](./2024/21-callbacks/solution.ts) |
 | 22  | [Funciones de Orden Superior](https://retosdeprogramacion.com/roadmap/)                      |     🔴     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/22-funciones-de-orden-superior/index.js) |
 | 23  | [Patrones de Diseño: Singleton](https://retosdeprogramacion.com/roadmap/)                    |     🟡     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/23-singleton/index.js) |
 | 24  | [Patrones de Diseño: Decoradores](https://retosdeprogramacion.com/roadmap/)                  |     🟢     | [![JavaScript](https://img.shields.io/badge/-JavaScript-F7DF1E?style=flat&logo=javascript&logoColor=black)](./2024/24-decoradores/index.js) |