Fix broken links in README documentation.
Fix broken links in README documentation.

kuujo/copycat,tempbottle/copycat,tempbottle/copycat,atomix/atomix,madjam/copycat,madjam/copycat,aruanruan/copycat,quantiply-fork/copycat,aruanruan/copycat,arnonmoscona/copycat,atomix/atomix,kuujo/copycat,arnonmoscona/copycat