Say how to run tests in the readme

README.md

@@ -7,3 +7,11 @@
 :scroll: The source is in [instantpage.js](https://github.com/instantpage/instant.page/blob/master/instantpage.js).
 
 :star2: Star this repository to follow its development.
+
+## Tests
+
+With [Node](https://nodejs.org/), run:
+
+`node test/app.js`
+
+And access http://127.0.0.1:8000/. Or specify another port with an argument after the filename.