Add SubStringy to readme
Add SubStringy to readme

Big-Shark/Stringy,marktopper/Stringy,danielkesselberg/Stringy,taohaoge/Stringy,bocharsky-bw/Stringy,voku/Stringy,danielstjules/Stringy,sofyansitorus/Stringy,ycms/Stringy,ihsanudin/Stringy,wallacesilva/Stringy