Add burndown panel

src/App.tsx

@@ -1,4 +1,5 @@
 import Board from './Board';
+import Burndown from './Burndown';
 import TaskEditor from './TaskEditor';
 import React, { useState } from "react";
 import VSCodeApi from "./VSCodeApi";
@@ -94,6 +95,11 @@ function App() {
           vscode={vscode}
         />
       }
+      {
+        type === 'burndown' &&
+        <Burndown
+        />
+      }
     </React.Fragment>
   );
 }

src/Burndown.tsx

@@ -0,0 +1,9 @@
+import React from 'react';
+
+const Burndown = () => {
+  return (
+    <div>burndown chart</div>
+  );
+};
+
+export default Burndown;