fix some backtick syntax from my head being in markdown land
Add a navigational link to the sidebar for _.before
Added navigation link on sidebar for _.noop
Merge pull request #1801 from dreyacosta/master

Added navigation link on sidebar for _.noop
document some things missed before
Merge pull request #1803 from akre54/doc-fixes

document some things missed before
Merge branch 'master' into gh-pages
add note to changelog about _.union and _.difference only accepting arrays