Merge pull request #18 from wbprice/gh-pages

css updates
Merge pull request #19 from wbprice/gh-pages

donor page link and venue updates
Merge pull request #20 from wbprice/gh-pages

added image to git because I forgot.
replace lorem, edit intro
Merge pull request #21 from kmcurry/gh-pages

replace lorem, edit intro
adding new challenge and changing old to activities
add fork me ribbon for #23
fix url
Merge pull request #24 from kmcurry/gh-pages

Add fork me ribbon for #23
change ribbon to gray

would be even better if we have cfa colored ribbons. couldn't find or quickly make.
make images responsive, challenge text white, add challenge image margin.