add chart line demo and add storybook

src/demos/LineChart/LineChartExample.tsx

@@ -0,0 +1,14 @@
+import React from 'react';
+import { ReactChartJs } from '@cubetiq/react-chart-js';
+
+function LineChartExample(props: any) {
+    const { chartConfig } = props
+
+    return (
+        <ReactChartJs
+            chartConfig={chartConfig}
+        />
+    );
+}
+
+export default LineChartExample;