Update README.markdown

The markdown is generating a weird link: 

<p>Please use <a href="/jed/cookie-node/blob/master/jed/cookies">Cookies</a> instead.

and it should be

<p>Please use <a href="/jed/cookies">Cookies</a> instead.

I made the link more explicit. (https://github.com/jed/cookies)
Merge pull request #15 from paulmars/patch-1

Made link more explicit, the markdown generation was creating a relative path incorrectly.