Changed the excerpt a bit

Signed-off-by: Conrad Gomes <conrad.s.j.gomes@gmail.com>
Adding post from http://techeuphoria.blogspot.in/2013/12/linux-linked-lists.html

Signed-off-by: Conrad Gomes <conrad.s.j.gomes@gmail.com>
Added author_url = https://www.linkedin.com/in/conradsjgomes

Signed-off-by: Conrad Gomes <conrad.s.j.gomes@gmail.com>
Commented the author_url picture

Signed-off-by: Conrad Gomes <conrad.s.j.gomes@gmail.com>