scaladoc (i.e. run `SKIP_SCALADOC=1 jekyll`).
which generates scala doc by calling `sbt/sbt doc`, copies it over to docs, and updates the links from the api webpage to now point to the copied over scaladoc (making the _site directory easy to just copy over to a public website).
easier to read.
docs/README.md to describe use of Jekyll, and renmaed things to make them more consistent with the lower-case-with-hyphens convention.