Add search shortcut

src/client/app.vue

@@ -193,6 +193,7 @@ export default Vue.extend({
 			return {
 				'p': this.post,
 				'n': this.post,
+				's': this.search,
 				'h|/': this.help
 			};
 		},

src/docs/keyboard-shortcut.ja-JP.md

@@ -10,6 +10,7 @@
 		<tr><td><kbd class="key">P</kbd>, <kbd class="key">N</kbd></td><td>新規投稿</td><td><b>P</b>ost, <b>N</b>ew, <b>N</b>ote</td></tr>
 		<tr><td><kbd class="key">T</kbd></td><td>タイムラインの最も新しい投稿にフォーカス</td><td><b>T</b>imeline, <b>T</b>op</td></tr>
 		<tr><td><kbd class="group"><kbd class="key">Shift</kbd> + <kbd class="key">N</kbd></kbd></td><td>通知を表示/隠す</td><td><b>N</b>otifications</td></tr>
+		<tr><td><kbd class="key">S</kbd></td><td>検索</td><td><b>S</b>earch</td></tr>
 		<tr><td><kbd class="key">H</kbd>, <kbd class="key">?</kbd></td><td>ヘルプを表示</td><td><b>H</b>elp</td></tr>
 	</tbody>
 </table>