Add Code folding on CSS style tab

shared/naturalcrit/codeEditor/fold-pages.js

@@ -0,0 +1,26 @@
+module.exports = {
+	registerHomebreweryHelper : function(CodeMirror) {
+		CodeMirror.registerHelper('fold', 'homebrewery', function(cm, start) {
+			const matcher = /^\\page.*/;
+			const prevLine = cm.getLine(start.line - 1);
+
+			if(start.line === cm.firstLine() || prevLine.match(matcher)) {
+				const lastLineNo = cm.lastLine();
+				let end = start.line;
+
+				while (end < lastLineNo) {
+					if(cm.getLine(end + 1).match(matcher))
+						break;
+					++end;
+				}
+
+				return {
+					from : CodeMirror.Pos(start.line, 0),
+					to   : CodeMirror.Pos(end, cm.getLine(end).length)
+				};
+			}
+
+			return null;
+		});
+	}
+};