fix(config): site.baseurl default value is root.

When adding additional pages to the site, the css links can get
messed up until you go back and set a `baseurl` entry in the config.

This makes sense to add this since the project comes with entries for
`baseurl` at the beginning.
Merge pull request #48 from Droogans/site.baseurl-default-value

fix(config): site.baseurl default value is root.