trick to prevent DOI to be badly formated

Author: jchiquet

README.md

@@ -10,7 +10,7 @@ illustrate the Computo spirit.*
 
 [![build and
 publish](https://github.com/computorg/published-paper-tsne/actions/workflows/build.yml/badge.svg)](https://github.com/computorg/published-paper-tsne/actions/workflows/build.yml)
-[![DOI:10.57750/xx-xxx](https://img.shields.io/badge/DOI-10.57750/xx-xxx-034E79.svg)](https://doi.org/10.57750/xx-xxx)
+[![DOI:10.57750/xxxxxx](https://img.shields.io/badge/DOI-10.57750/xxxxxx-034E79.svg)](https://doi.org/10.57750/xxxxxx)
 <!-- [![reviews](https://img.shields.io/badge/review-report-blue)](https://github.com/computorg/published-paper-tsne/issues?q=is%3Aopen+is%3Aissue+label%3Areview) -->
 [![Creative Commons
 License](https://i.creativecommons.org/l/by/4.0/80x15.png)](http://creativecommons.org/licenses/by/4.0/)