Link to d3-hexbin and d3-sankey

README.md

@@ -1,3 +1,8 @@
 # D3 Plugins
 
+These plugins are not compatible with the latest version of D3, V4. For the latest versions, see:
+
+* [d3-hexbin](https://github.com/d3/d3-hexbin)
+* [d3-sankey](https://github.com/d3/d3-sankey)
+
 Please note: the plugins in this repository will soon be broken up into separate repositories for easier distributed ownership. If you have a new plugin you’d like to share, please add a link to it from the [D3 plugins wiki](https://github.com/mbostock/d3/wiki/Plugins).