Some improvement to example notebook
Some improvement to example notebook

split on heading cell to have anchor and link back to homepage

hainesr/iruby,astroboxio/iruby,domitry/iruby,astroboxio/iruby,Rambatino/pi-ruby,zalt50/iruby,zalt50/iruby,zalt50/iruby,zalt50/iruby,hainesr/iruby,SciRuby/iruby,SciRuby/iruby,SciRuby/iruby,SciRuby/iruby,mijoharas/iruby,Rambatino/pi-ruby,mijoharas/iruby,jjn2009/iruby,jjn2009/iruby,domitry/iruby