I agree, and to go further, even _if_ a non-developer did on github (maybe higher in the search rankings), for many popular projects you can generally find the consumer facing url via the "homepage" link.

Example: https://github.com/rack/rack homepage url points to http://rack.rubyforge.org/

https://github.com/tenderlove/nokogiri => http://nokogiri.org/

https://github.com/mxcl/homebrew => http://mxcl.github.com/homebrew/

https://github.com/joyent/node => http://nodejs.org/

etc, etc.

It also seems fairly common to put the 'consumer' url near the top or bottom of the README.