add shield for OSSF

Author: mdo

README.md

@@ -70,6 +70,7 @@ Read the [Getting started page](https://getbootstrap.com/docs/5.3/getting-starte
 [![CSS Brotli size](https://img.badgesize.io/twbs/bootstrap/main/dist/css/bootstrap.min.css?compression=brotli&label=CSS%20Brotli%20size)](https://github.com/twbs/bootstrap/blob/main/dist/css/bootstrap.min.css)
 [![JS gzip size](https://img.badgesize.io/twbs/bootstrap/main/dist/js/bootstrap.min.js?compression=gzip&label=JS%20gzip%20size)](https://github.com/twbs/bootstrap/blob/main/dist/js/bootstrap.min.js)
 [![JS Brotli size](https://img.badgesize.io/twbs/bootstrap/main/dist/js/bootstrap.min.js?compression=brotli&label=JS%20Brotli%20size)](https://github.com/twbs/bootstrap/blob/main/dist/js/bootstrap.min.js)
+![OSSF-Scorecard Score](https://img.shields.io/ossf-scorecard/github.com/twbs/bootstrap)
 [![Backers on Open Collective](https://img.shields.io/opencollective/backers/bootstrap?logo=opencollective&logoColor=fff)](#backers)
 [![Sponsors on Open Collective](https://img.shields.io/opencollective/sponsors/bootstrap?logo=opencollective&logoColor=fff)](#sponsors)