doc nonlinear mapping estimation

Author: rflamary

README.md

@@ -62,6 +62,8 @@ The examples folder contain several examples and use case for the library. The f
 * [Color transfer in images](https://github.com/rflamary/POT/blob/master/examples/Demo_Image_ColorAdaptation.ipynb)
 * [OT mapping estimation for domain adaptation](https://github.com/rflamary/POT/blob/master/examples/Demo_2D_OTmapping_DomainAdaptation.ipynb)
 
+You can also see the notebooks with [Jupyter nbviewer](https://nbviewer.jupyter.org/github/rflamary/POT/tree/master/examples/).
+
 ## Acknowledgements
 
 The contributors to this library are:

docs/source/readme.rst

@@ -86,6 +86,9 @@ Here is a list of the Python notebooks if you want a quick look:
 -  `OT mapping estimation for domain
    adaptation <https://github.com/rflamary/POT/blob/master/examples/Demo_2D_OTmapping_DomainAdaptation.ipynb>`__
 
+You can also see the notebooks with `Jupyter
+nbviewer <https://nbviewer.jupyter.org/github/rflamary/POT/tree/master/examples/>`__.
+
 Acknowledgements
 ----------------