Fixed typo in README.rdoc. Interpolated values in translations need double brackets
Fixed typo in README.rdoc. Interpolated values in translations need double brackets

muthhus/responders,gpr/responders,pravi/responders,telekomatrix/responders,muthhus/responders,telekomatrix/responders,pravi/responders,plataformatec/responders,plataformatec/responders,gpr/responders,plataformatec/responders