Update ossf score (#41816)

* [ossf] remove binary files

A check found 16 binary files in our repo. Remove them.

* Add OSSF badge display

README.md

@@ -7,6 +7,7 @@
 [![GitHub pulls-opened](https://img.shields.io/github/issues-pr/dotnet/docs.svg)](https://GitHub.com/dotnet/docs/pulls?q=is%3Aissue+is%3Aopened)
 [![GitHub pulls-merged](https://img.shields.io/github/issues-search/dotnet/docs?label=merged%20pull%20requests&query=is%3Apr%20is%3Aclosed%20is%3Amerged&color=darkviolet)](https://github.com/dotnet/docs/pulls?q=is%3Apr+is%3Aclosed+is%3Amerged)
 [![GitHub pulls-unmerged](https://img.shields.io/github/issues-search/dotnet/docs?label=unmerged%20pull%20requests&query=is%3Apr%20is%3Aclosed%20is%3Aunmerged&color=red)](https://github.com/dotnet/docs/pulls?q=is%3Apr+is%3Aclosed+is%3Aunmerged)
+[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/9215/badge)](https://www.bestpractices.dev/projects/9215)
 
 This repository contains the conceptual documentation for .NET. The [.NET documentation site](https://learn.microsoft.com/dotnet) is built from multiple repositories in addition to this one: