more pkg examples

pkg/README.md

@@ -12,6 +12,7 @@ Examples:
 * https://github.com/istio/istio/tree/master/pkg
 * https://github.com/google/gvisor/tree/master/pkg
 * https://github.com/google/syzkaller/tree/master/pkg
+* https://github.com/perkeep/perkeep
 * https://github.com/minio/minio/tree/master/pkg
 * https://github.com/heptio/ark/tree/master/pkg
 * https://github.com/heptio/sonobuoy/tree/master/pkg