fix README links to docs

[Laoujin]

Fixed 2 links in the README to the docs website.

I just went ahead and clicked all links and found that the link to the independent performance benchmark mustache vs handlebars is down:
http://sorescode.com/2010/09/12/benchmarks.html
I was unable to find it anywhere else on the web.

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[jaylinski]

Thank you!

[Laoujin]

@jaylinski : What do you want to do with the independent benchmarks that is currently down?

As I said, I couldn't really find anything else, nor could I find the blog post on his github account :(

If you'd merge it, I can create a new independent blog post 😀

[jaylinski]

@Laoujin If you create a blog post, I would link it in the readme, yes.