Add OpenSSF Best Practices badge to README

README.md

@@ -20,6 +20,7 @@ Documentation: [https://escape2020.pages.in2p3.fr/wp3/eossr/](https://escape2020
 https://gitlab.in2p3.fr/escape2020/wp3/eossr/-/commits/master)
 [![](https://gitlab.in2p3.fr/escape2020/wp3/eossr/badges/master/coverage.svg)](
 https://gitlab.in2p3.fr/escape2020/wp3/eossr/-/commits/master)
+[![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/5712/badge)](https://bestpractices.coreinfrastructure.org/projects/5712)
 [![](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 [![](https://zenodo.org/badge/DOI/10.5281/zenodo.5524912.svg)](https://doi.org/10.5281/zenodo.5524912)
 [![](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/git/https%3A%2F%2Fgitlab.in2p3.fr%2Fescape2020%2Fwp3%2Feossr/HEAD)