chore: add OpenSSF badge

Signed-off-by: Felipe Zipitria <felipe.zipitria@owasp.org>

README.md

@@ -8,7 +8,7 @@
 [![Total alerts](https://img.shields.io/lgtm/alerts/g/coreruleset/go-ftw.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/coreruleset/go-ftw/alerts/)
 [![Coverage](https://sonarcloud.io/api/project_badges/measure?project=coreruleset_go-ftw&metric=coverage)](https://sonarcloud.io/dashboard?id=coreruleset_go-ftw)
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=coreruleset_go-ftw&metric=alert_status)](https://sonarcloud.io/dashboard?id=coreruleset_go-ftw)
-
+[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/8633/badge)](https://www.bestpractices.dev/projects/8633)
 
 Go-FTW is a replacement for [FTW](https://pypi.org/project/ftw/) which had reached its limits in terms of maintainability and performance.