Update README
Update README

- add release grunt parameter to build the whole thing.
cedricpinson/osgjs,kkuunnddaannkk/osgjs,kkuunnddaannkk/osgjs,cedricpinson/osgjs,cedricpinson/osgjs,jtorresfabra/osgjs,hishamabdelrahman/osgjs,jtorresfabra/osgjs,gideonmay/osgjs,jmirabel/osgjs,jmirabel/osgjs,jmirabel/osgjs,gideonmay/osgjs,hishamabdelrahman/osgjs,hishamabdelrahman/osgjs,jtorresfabra/osgjs,kkuunnddaannkk/osgjs,gideonmay/osgjs