stringsync: create file for code and document basic idea
stringsync: create file for code and document basic idea

tscholl2/smc,DrXyzzy/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc