Should docs explain hosting on s3?

Thanks a lot for cryogen!

In order to get a cryogen site hosted as a static s3 site, I needed to make a couple configuration changes. Perhaps there should be a dedicated page in the docs for that? If you'd like a PR for that I'll provide it, but the gist of it is just:

In config.edn:
- set `:blog-prefix` to "/"
- set `:clean-urls` to false

Then copy resources/public/ to s3. With aws cli, that's
``` bash
aws s3 cp /PATH/TO/resources/public/ s3://BUCKET/ --recursive
```