add md-page to people who use (#604)

README.md

@@ -25,6 +25,7 @@ Check a live Demo here http://demo.showdownjs.com/
  - [Meteor](https://www.meteor.com/)
  - [Stackexchange](http://stackexchange.com/) - forked as [PageDown](https://code.google.com/p/pagedown/)
  - [docular](https://github.com/Vertafore/docular)
+ - [md-page](https://github.com/oscarmorrison/md-page)
  - [and some others...](https://www.npmjs.com/browse/depended/showdown)
 
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