Update README.md

Feature branch to identify problems to my gh-pages blog built using jekyll. 

Setting up a github project pages blog using jekyll, but the links to my assets files do not work properly. When trying to add an image to my post the image does not show. When I try to link to a pdf for download I get a dead link (as in `http://nikosdaniilidis/github.io/assets/all-pdf/Daniilidis2014-surface-noise.pdf`)