fix links from index.html
fix links from index.html

Without the trailing "/", the reference to "../sample-images" is wrong
mosoft521/Wookmark-jQuery,mosoft521/Wookmark-jQuery,germanysbestkeptsecret/Wookmark-jQuery,mosoft521/Wookmark-jQuery,germanysbestkeptsecret/Wookmark-jQuery,germanysbestkeptsecret/Wookmark-jQuery