feat(storybook): refine manager layout and Hanmac branding

.storybook/manager.js

@@ -31,13 +31,14 @@ document.head.appendChild(toolbarStyle)
 addons.setConfig({
   layout: {
     showPanel: false,
+    showToolbar: false,
     // LNB width 246px. recentVisibleSizes keeps the same width when the sidebar is collapsed and expanded again.
     navSize: 246,
     recentVisibleSizes: { navSize: 246 },
   },
   theme: create({
     base: 'light',
-    brandTitle: 'HM Design System',
+    brandTitle: 'Hanmac Design System',
     brandUrl: './',
     brandTarget: '_self',
     fontBase: "'Hanmac Manager Noto Sans KR', 'Noto Sans KR', 'Malgun Gothic', sans-serif",