kijiproject.github.com: DOCS-138. Change Express Userguide sections temporarily for first release.

issue: https://jira.kiji.org/browse/DOCS-138
review: https://review.kiji.org/r/1417
commit: https://github.com/kijiproject/kijiproject.github.com/commit/debf3b1edf65daf0fc4fe07e9825d059cd9a243d