Docs: Add OpenSSF Best Practice Badge

(fixes #37)

Author: uniqueck

README.md

@@ -4,3 +4,4 @@
 [![npm version](http://img.shields.io/npm/v/htmlsanitycheck.svg)](https://www.npmjs.com/package/htmlsanitycheck)
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=uniqueck_htmlSanityCheck.js&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=uniqueck_htmlSanityCheck.js)
 [![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/uniqueck/htmlSanityCheck.js/badge)](https://scorecard.dev/viewer/?uri=github.com/uniqueck/htmlSanityCheck.js)
+[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/9391/badge)](https://www.bestpractices.dev/projects/9391)