implement test VCO redux state and actions

src/App.js

@@ -1,17 +1,19 @@
 import React from 'react';
 import logo from './logo.svg';
 import { Counter } from './features/counter/Counter';
+import { Timbre } from './features/timbre/Timbre';
 import './App.css';
 
 function App() {
-  return (
-    <div className="App">
-      <header className="App-header">
-        <img src={logo} className="App-logo" alt="logo" />
-        <Counter />
-      </header>
-    </div>
-  );
+    return (
+        <div className="App">
+            <header className="App-header">
+                <img src={logo} className="App-logo" alt="logo" />
+                <Counter />
+                <Timbre />
+            </header>
+        </div>
+    );
 }
 
 export default App;