Update example usage in help.html for vigilnzScan

Author: Susenthiran28

src/main/resources/io/jenkins/plugins/vigilnz/pipeline/PipelineStep/help.html

@@ -5,10 +5,11 @@
     <p>
         Example usage:
     </p>
-    <pre>
-        vigilnzSecurityScan scanTypes: 'cve,sbom,sast'
-    </pre>
+      <pre>
+        vigilnzScan credentialsId: 'my-creds', scanTypes: 'cve,sbom,sast'
+      </pre>
     <p>
         <b>scanTypes:</b> Comma-separated list of scan types to run.
     </p>
 </div>
+