add warning

Author: CarloLucibello

README.md

@@ -13,9 +13,11 @@ This package is a part of the
 Its functionality is built on top of the package
 [DataDeps.jl](https://github.com/oxinabox/DataDeps.jl).
 
-
 ## Available Datasets
 
+**Warning**: this package is under heavy redesign. The link belows point to the documentation for the yet to be released version. 
+For the tagged version instead, please consult the [stable docs](https://JuliaML.github.io/MLDatasets.jl/stable) 
+
 Datasets are grouped into different categories. Click on the links below for a full list of datasets available in each category.
 
 - [Graphs](https://juliaml.github.io/MLDatasets.jl/dev/datasets/graphs) - Datasets with an underlying graph structure: Cora, PubMed, CiteSeer, ...