add example section (#14)

* add example section

* apply corrections

Author: umbynos

README.md

@@ -31,6 +31,11 @@ To pin the exact version:
     version: "0.5.0"
 ```
 
+## Examples
+
+[Here][example] there is a good example on how to use the action.
+See also the [Arduino on GitHub Actions blogpost][blogpost] to learn more.
+
 ## Development
 
 To work on the codebase you have to install all the dependencies:
@@ -57,3 +62,5 @@ See the [official Github documentation][pat-docs] to know more about Personal Ac
 6. open a PR and request a review.
 
 [pat-docs]: https://docs.github.com/en/github/authenticating-to-github/creating-a-personal-access-token
+[example]: https://github.com/arduino/arduino-cli-example/blob/master/.github/workflows/test.yaml
+[blogpost]: https://blog.arduino.cc/2019/11/14/arduino-on-github-actions/