don't track _theme_packages directory
don't track _theme_packages directory

This should be treated as a staging directory

jhu-chang/jhu-chang.github.io,aadm/aadm.github.io,jhu-chang/jhu-chang.github.io,P4F/p4f.github.com,jershmagersh/p4f.github.com,jhu-chang/jhu-chang.github.io,aadm/aadm.github.io