Example in README for Regexp register_uri

[akahn]

I didn't realize fakeweb had this feature until I searched the Google Groups list (well, I would have realized had I read the issues here).

I propose adding an example of this to the README, in addition to the brief mention it gets. I've done this over in akahn/fakeweb@d6076cf.

Let me know your thoughts on this addition.

[chrisk]

Sounds great, thanks for the patch. I'd kept the mention brief in the README before because it was an "experimental" feature when we first added it.

[chrisk]

OK, merged.