Correct spellling error in configuration.md
SPARK-917 Improve API links in nav bar
Merge pull request #239 from aarondav/nit

Correct spellling error in configuration.md
Merge pull request #240 from pwendell/master

SPARK-917 Improve API links in nav bar
Various broken links in documentation
Adding HDP 2.0 version
Small fix
Merge pull request #242 from pwendell/master

Update broken links and add HDP 2.0 version string

I ran a link checker on the UI and found several broken links.