get rid of docs warning

Author: Gregory Pett

src/main/java/org/kohsuke/github/GHCodeScanningAlert.java

@@ -132,6 +132,8 @@ public String getRuleName() {
 
     /**
      * Get the code scanning security severity level
+     *
+     * @return the scanningSecurityLevel
      */
     public String getScanningSecurityLevel() {
         return rule.security_severity_level;