docs: Add openssf scorecard badge (#2919)

Author: utpilla

README.md

@@ -3,10 +3,11 @@
 The Rust [OpenTelemetry](https://opentelemetry.io/) implementation.
 
 [![Crates.io: opentelemetry](https://img.shields.io/crates/v/opentelemetry.svg)](https://crates.io/crates/opentelemetry)
-[![Documentation](https://docs.rs/opentelemetry/badge.svg)](https://docs.rs/opentelemetry)
 [![LICENSE](https://img.shields.io/crates/l/opentelemetry)](./LICENSE)
 [![GitHub Actions CI](https://github.com/open-telemetry/opentelemetry-rust/workflows/CI/badge.svg)](https://github.com/open-telemetry/opentelemetry-rust/actions?query=workflow%3ACI+branch%3Amain)
+[![Documentation](https://docs.rs/opentelemetry/badge.svg)](https://docs.rs/opentelemetry)
 [![codecov](https://codecov.io/gh/open-telemetry/opentelemetry-rust/branch/main/graph/badge.svg)](https://codecov.io/gh/open-telemetry/opentelemetry-rust)
+[![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/open-telemetry/opentelemetry-rust/badge)](https://scorecard.dev/viewer/?uri=github.com/open-telemetry/opentelemetry-rust)
 [![Slack](https://img.shields.io/badge/slack-@cncf/otel/rust-brightgreen.svg?logo=slack)](https://cloud-native.slack.com/archives/C03GDP0H023)
 
 ## Overview