Script to generate and publish docs

[greglook]

Expand the current doc/build.sh script to both (re)generate documentation for the project and set up the directory to push to the gh-pages branch. Documentation includes:

• API documentation with codox.
• Code documentation with Marginalia.
• Namespace hierarchy with lein-hiera.
• Rendered doc markdown files.
• An index page linking to everything.

See the codox wiki for publishing instructions.