chore: Add OSS-Fuzz badge (#6703)

Follows google/oss-fuzz#13062

Author: pellared

README.md

@@ -6,6 +6,7 @@
 [![Go Report Card](https://goreportcard.com/badge/go.opentelemetry.io/otel)](https://goreportcard.com/report/go.opentelemetry.io/otel)
 [![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/open-telemetry/opentelemetry-go/badge)](https://scorecard.dev/viewer/?uri=github.com/open-telemetry/opentelemetry-go)
 [![OpenSSF Best Practices](https://www.bestpractices.dev/projects/9996/badge)](https://www.bestpractices.dev/projects/9996)
+[![Fuzzing Status](https://oss-fuzz-build-logs.storage.googleapis.com/badges/opentelemetry-go.svg)](https://issues.oss-fuzz.com/issues?q=project:opentelemetry-go)
 [![Slack](https://img.shields.io/badge/slack-@cncf/otel--go-brightgreen.svg?logo=slack)](https://cloud-native.slack.com/archives/C01NPAXACKT)
 
 OpenTelemetry-Go is the [Go](https://golang.org/) implementation of [OpenTelemetry](https://opentelemetry.io/).