docs: update the location for React Testing Examples (#1059)

* Just add an alternative location for the React Testing Examples

I am in no way affiliated with the project, I just wanted to add a link that was not dead.

* Update link to point directly at the netlify domain

Author: tarjei

docs/example-external.mdx

@@ -6,8 +6,7 @@ sidebar_label: External Examples
 
 ## Code Samples
 
-- You can find more React Testing Library examples at
-  [react-testing-examples.com](https://react-testing-examples.com/jest-rtl/).
+- You can find more React Testing Library examples at [https://react-testing-examples.netlify.app/](https://react-testing-examples.netlify.app/).
 
 ## Playground