Add link to API reference

README.md

@@ -17,6 +17,10 @@ To install all its package definitions, run:
 ./scripts/feeds install -a -p luci
 ```
 
+## API Reference
+
+You can browse the generated API documentation [directly on Github](http://htmlpreview.github.io/?http://raw.githubusercontent.com/openwrt/luci/master/documentation/api/index.html).
+
 ## License
 
 See [LICENSE](LICENSE) file.