update search help

resource/locales/ja/translation.json

@@ -208,6 +208,12 @@
     },
     "exclude_prefix": {
       "desc": "ページ名が {{path}} から始まるページを除外"
+    },
+    "tag": {
+      "desc": "{{tag}} というタグを含むページを検索"
+    },
+    "exclude_tag": {
+      "desc": "{{tag}} というタグを含むページを除外"
     }
   },
   "search": {

src/client/js/components/SearchForm.js

@@ -72,6 +72,14 @@ export default class SearchForm extends React.Component {
             <th className="text-right pt-2"><code>-prefix:/user/</code></th>
             <td><h6 className="m-0 pt-1">{ t('search_help.exclude_prefix.desc', { path: '/user/' }) }</h6></td>
           </tr>
+          <tr>
+            <th className="text-right pt-2"><code>tag:wiki</code></th>
+            <td><h6 className="m-0 pt-1">{ t('search_help.tag.desc', { tag: 'wiki' }) }</h6></td>
+          </tr>
+          <tr>
+            <th className="text-right pt-2"><code>-tag:wiki</code></th>
+            <td><h6 className="m-0 pt-1">{ t('search_help.exclude_tag.desc', { tag: 'wiki' }) }</h6></td>
+          </tr>
         </tbody>
       </table>
     );