Best practices for adding online help to Vaadin application

We have built a functional Vaadin app and we now have a requirement to provide some sort of online help for our users. This can be very simple and doesn’t need to be contextual although I can see that maybe a future requirement.

I am trying to figure out the best/easiest way to implement this functionality.

Our application runs in our own sandbox environment (JVM+Tomcat, no access to external internet) and the help will likely be generated by our doc people in the form of HTML pages.

Any opinions, suggestions, or prior experiences would be greatly appreciated!

I created a PDF and use com.vaadin.server.BrowserWindowOpener
to open it from a button.