Explain this file purpose

Add a detailed license header and a comment that explains to external customers the purpose of this file.

Author: younesAmin

sbom_generation.yaml

@@ -1,5 +1,9 @@
 # Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
 
+# This OCI DevOps build specification file [1] generates a Software Bill of Materials (SBOM) of the repository.
+# The file is needed to run checks for third-party vulnerabilities and business approval according to Oracle’s GitHub policies.
+# [1] https://docs.oracle.com/en-us/iaas/Content/devops/using/build_specs.htm
+
 version: 0.1
 component: build
 timeoutInSeconds: 1000