Github is a script repository.
I don't use version control myself, but it's in DW. It's helpful if you work in teams and need to check files in & out of the remote server. Or, if you maintain a site with 2 computers -- one at office, one at home. This help article explains how to use version control to check-in / check-out files with Dreamweaver
http://help.adobe.com/en_US/dreamweaver/cs/using/WSc78c5058ca073340dcd a9110b1f693f21-7ebfa.html
Nancy O.