fix broken merge

Author: MatanBobi

docs/react-testing-library/intro.mdx

@@ -18,11 +18,11 @@ npm install --save-dev @testing-library/react @testing-library/dom
 
 ### With TypeScript
 
-To get full type coverage, you need to install the types for `react-dom` as
+To get full type coverage, you need to install the types for `react` and `react-dom` as 
 well:
 
 ```bash npm2yarn
-npm install --save-dev @testing-library/react @testing-library/dom @types/react-dom
+npm install --save-dev @testing-library/react @testing-library/dom @types/react @types/react-dom
 ```
 
 [gh]: https://github.com/testing-library/react-testing-library