update Readme to reflect content moved to demo page

Readme.md

@@ -3,5 +3,6 @@
 Abba is a Javascript library for A/B test analysis. It analyzes tests with binomial outcomes for any
 number of groups. You can use the library (in `abba/`) to just compute statistics or to render a
 nice table summarizing those statistics. There's a handy little app in `demo/` which demonstrates
-how to use the library. You can find plenty more details in `demo/abba.html` or on the [live
-demo](http://www.thumbtack.com/labs/abba).
+how to use the library.
+
+You can find plenty more details on the [live demo](http://www.thumbtack.com/labs/abba).