All static files that you want to serve should be in the root directory of your repository. No need to use a separate `www` folder. `buildpack-nginx` will automatically download the buildpack, download NGINX, compile it, and install it. The next time you push your project, the buildpack will reuse the precompiled binaries.
By default, this buildpack will 404 if a requested file is not found. For static sites that use the browser's history router to show the correct context, setting the `NGINX_DEFAULT_REQUEST` to a specific file will override this.
You may completely override the built-in nginx config by placing an `app-nginx.conf.sigil` file in the root, modeled after our own [`conf/app-nginx.conf.sigil`](https://github.com/dokku/buildpack-nginx/blob/master/conf/app-nginx.conf.sigil). This will be used inside of the container, and not by the host Dokku instance. See the [sigil project](https://github.com/gliderlabs/sigil) for more information concerning the sigil format.