Update readme to link to previous versions

Note - this removed now not required mention of liquid tags in docs.

README.md

@@ -20,7 +20,7 @@ CDN: https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.0.0/Chart.js
 
 ## Documentation
 
-You can find documentation at [www.chartjs.org/docs](http://www.chartjs.org/docs). The markdown files that build the site are available under `/docs`. Please note - in some of the json examples of configuration you might notice some liquid tags - this is just for the generating the site html, please disregard.
+You can find documentation at [www.chartjs.org/docs](http://www.chartjs.org/docs). The markdown files that build the site are available under `/docs`. Previous version documentation is available at [www.chartjs.org/docs/#notes-previous-versions](http://www.chartjs.org/docs/#notes-previous-versions).
 
 ## Contributing