Add base CSS

Author: felipeog

src/css/base.css

@@ -0,0 +1,5 @@
+*,
+*::before,
+*::after {
+  box-sizing: border-box;
+}

src/index.tsx

@@ -1,6 +1,7 @@
 import * as ReactDOM from 'react-dom'
 
 import './css/reset.css'
+import './css/base.css'
 import { App } from './App'
 
 ReactDOM.render(<App />, document.getElementById('root'))