refactor: add init option for chart

web/index.js

@@ -5,6 +5,21 @@ var editor = CodeMirror.fromTextArea(document.getElementById("codeInput"), {
     mode: "javascript"
 });
 editor.setSize("100%", height);
+editor.setValue(`option = {
+    xAxis: {
+      type: 'category',
+      data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
+    },
+    yAxis: {
+      type: 'value'
+    },
+    series: [
+      {
+        data: [150, 230, 224, 218, 135, 147, 260],
+        type: 'line'
+      }
+    ]
+};`);
 
 function run() {
     var option = editor.getValue();