- Introduce the `Asset` type to distinguishing between static files and generated files. The later can be one of `Html` or `Other`, allowing the live server to handle them sensibly.
-`Ema` typeclass:
- Drop `staticAssets` in favour of `allRoutes` (renamed from `staticRoutes`) returning all routes including both generated and static routes.
- Drop `Slug` and use plain `FilePath`. Route encoder and decoder deal directly with the on-disk path of the generated (or static) files.
- Make the render function (which `runEma` takes) return a `Asset LByteString` instead of `LByteString` such that it can handle all routes, and handle static files as well as generation of non-HTML content (eg: RSS)
- now returns relative URLs (ie. without the leading `/`)
- Use the `<base>` tag to specify an explicit prefix for relative URLs in generated HTML. This way hosting on GitHub Pages without CNAME will continue to have functional links.