update README to upstream (Formtastic) 2.2+ API spec
update README to upstream (Formtastic) 2.2+ API spec

mjbellantoni/formtastic-bootstrap,0xCCD/formtastic-bootstrap,epotocko/formtastic-bootstrap,paulodiovani/formtastic-bootstrap,ekampp/formtastic-foundation,rcode5/formtastic-bootstrap,jibiel/formtastic-bootstrap,9nonnatus/formtastic-bootstrap,sodabrew/formtastic-bootstrap