Fixed documentation links in Readme.markdown
Fixed documentation links in Readme.markdown

jiakai-lian/SimpleAuth,hyperspacemark/SimpleAuth,tofaruk/SimpleAuth-1,AlexanderMazaletskiy/SimpleAuth,hoanganh6491/SimpleAuth,adamjmcgrath/SimpleAuth-1,martinpilch/SimpleAuth,sburavtsov/SimpleAuth,calebd/SimpleAuth,machelix/SimpleAuth