Se añadio comando para compilar sass en la documentacion

Author: AangPer

Diff for: README.md

@@ -66,3 +66,5 @@ This section has moved here: https://facebook.github.io/create-react-app/docs/de
 ### `yarn build` fails to minify
 
 This section has moved here: https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify
+
+### `npm run-script compile:sass` to compile sass