Add attribute for operator privileges (#2075)

Author: lcawl

shared/attributes.asciidoc

@@ -195,6 +195,7 @@ Common words and phrases
 
 :security:                X-Pack security
 :security-features:       security features
+:operator-feature:        operator privileges feature
 :es-security-features:    {es} {security-features}
 :stack-security-features: {stack} {security-features}
 :endpoint-sec:            Endpoint Security