Add notice to system info

[MAILPOET-949]

assets/js/src/help/system_info.jsx

@@ -13,7 +13,11 @@ function KnowledgeBase() {
 
       <Tabs tab="systemInfo" />
 
-      <div>asdfasdf</div>
+      <div className="mailpoet_notice notice inline notice-success" style={{marginTop: "1em"}}>
+        <p>{MailPoet.I18n.t('systemInfoIntro')}</p>
+      </div>
+
+      <textarea readOnly={true}></textarea>
     </div>
   );
 };