Update README.md

Minor change to readme
Merge pull request #17 from briandela/patch-1

Update README.md
Added the Seti theme
Adjust credit for Seti theme
Adjust credit for Seti theme
Add "Hipster Green" and "Jackie Brown" color schemes.
Added README links and credits for Hipster Green and Jackie Brown themes
Merge branch 'Unkulunkulu-master'
Added Chalk theme
Tweak Chalk screenshot
Added themes from zdj
Fix zdj credits
Added Spacedust
Tweak a couple of screenshots
Added Pencil Dark and Pencil Light
Added Flat theme
Fixed BirdsOfParadise scheme per #20
Added Atom, Brogrammer, and Darkside themes
Added Afterglow color scheme.
Merge pull request #21 from YabataDesign/master

Added Afterglow color scheme.