Add article testing library (testing-library#1055)

Add a link to the article 'Good testing practices with 🦔 Angular Testing Library' in Spanish.

Author: danywalls

docs/learning.mdx

@@ -57,5 +57,6 @@ sidebar_label: Learning Material
 
 - [TESTING en REACT 🧪 ¡Aprende DESDE CERO! Con react-testing-library y Jest](https://www.youtube.com/watch?v=KYjjtRgg_H0)
  by [Midudev](https://twitter.com/midudev)
+- [Buenas prácticas con Angular Testing Library](https://dev.to/danyparedes/buenas-practicas-con-angular-testing-library-59lp) by [Danywalls](https://twitter.com/danywalls)
 
 Feel free to contribute more!