Android - Should res/assets be marked as source?

I am just starting android development and the first thing that I noticed about the example project is that the res and assets directories are not marked as source.
I took this application as a starting point
http://blog.kerul.net/2012/12/flashcard-android-application.html
It has an html file in the assets dir and is accessed like this:

        webinfo=(WebView)findViewById(R.id.webinfo);
        //provide the URL path pointing to info.html
        webinfo.loadUrl("file:///android_asset/info.html");

The info.html doesn't auto-complete in the editor as resources normally do in java applications.
Is this because the assets dir is not marked as source in the project setup?