AI: address review on PR #477

frontend/src/components/TopNav.tsx

@@ -76,9 +76,12 @@ export const menuOutline = (
 	  { ...message ('add'), to: '/posts/new', visible: editable },
 	  { ...message ('allHistory'), to: '/posts/changes' },
 	  { ...message ('help'), to: '/wiki/ヘルプ:広場' }] },
-      { ...message ('tags'), to: '/tags', subMenu: [
+      { ...message ('tags'), to: '/tags',
+	base: pathName.startsWith ('/tag-descriptions') ? '/tag-descriptions' : '/tags',
+	subMenu: [
 	  { ...message ('master'), to: '/tags' },
 	  { ...message ('nicoLinks'), to: '/tags/nico' },
+	  { ...message ('tagDescriptions'), to: '/tag-descriptions' },
 	  { ...message ('allHistory'), to: '/tags/changes' },
 	  { ...message ('help'), to: '/wiki/ヘルプ:タグ' },
 	  { component: <Separator/>, visible: tagFlg },
@@ -101,7 +104,6 @@ export const menuOutline = (
 	  { ...message ('history'), to: `/materials/changes?material_id=${ material?.id }`,
 	    visible: materialFlg }] },
       ...([
-	  { key: 'tagDescriptions', path: '/tag-descriptions', type: 'tag_description' },
 	  { key: 'tagGroups', path: '/tag-groups', type: 'tag_group' }] as const)
 	  .map (({ key, path, type }): MenuVisibleItem => {
 	    const current = (wikiResourceType ?? 'tag_description') === type