fix link and add license to root readme

README.md

 # HDOC CONVERTER PROJECT
-
 ## What is Hdoc ?
-
-Please refer to the [Hdoc converter project website](http://hdoc.crzt.fr/www/co/hdocConverter.html)
+Please refer to the [Hdoc converter project website](http://hdoc.crzt.fr)
 >The aim of the project is to propose:
 >- a generic XML schema based on XHTML5 for documentary purpose (Hdoc format);
 >- a set of converters to transform document formats from and to Hdoc;
 >- a web site to manage the converters (Hdoc Converter Portal).
 
-## What is this repository ?
+## License
+All converters included into this repository are under [GNU General Public License](./LICENSE)
 
+## What is this repository ?
 This repository gathers some of the Hdoc converters, if not all of them.
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