Modernize Rubydoc.info service hook

Hey guys, I'm one of the rubydoc.info owners/maintainers. Updating our service hook here to bring it up to date. Let me know if you have any questions, and thanks in advance for the merge.
It looks like it should have been defaulted to the class name if the title was removed:

     Service::RDocInfo.title  => "RDocInfo" 

But I've gone ahead and updated it, since we're renamed the service to RubyDoc.info anyway. Thanks for taking a look at this, looking forward to getting it merged!