DOC: update read

README.md

@@ -136,7 +136,7 @@ as authors in the next software-paper publication.
 
 For more details see our [contribution policy](http://photon-hdf5.readthedocs.org/en/latest/contributing.html).
 
-## Authors
+## Authors & Contributors
 
 List of contributors (by lines of code):
 
@@ -146,5 +146,8 @@ List of contributors (by lines of code):
 - Xavier Michalet (@smXplorer) <michalet AT chem.ucla.edu>
 - Anders Barth (@AndersBarth) <anders.barth AT gmail.com>
 
+We thank also @ncodina for providing PTU files and helping in testing
+the PTU decoder in phconvert.
+
 ## Acknowledgements
 This work was supported by NIH Grant R01-GM95904.