Update configuration section of the README
Update configuration section of the README

Now contains information on using the spec_matcher config option.

uken/konacha,uken/konacha,uken/konacha,hugocorbucci/konacha,jfirebaugh/konacha,hugocorbucci/konacha,jfirebaugh/konacha,jfirebaugh/konacha,hugocorbucci/konacha