Add search syntax

src/text/parse/elements/search.ts

@@ -0,0 +1,13 @@
+/**
+ * Search
+ */
+
+module.exports = text => {
+	const match = text.match(/^(.+?) 検索(\n|$)/);
+	if (!match) return null;
+	return {
+		type: 'search',
+		content: match[0],
+		query: match[1]
+	};
+};