Add centering layout

client/placeholders/BrowserFrame.jsx

@@ -0,0 +1,18 @@
+import React from 'react';
+
+const BrowserFrame = ({ children }) => {
+    return (
+        <div className="br2 ba b--black-20">
+            <div className="flex pa3 bb b--black-20 items-center">
+                <div className="br-100 mr1 w1 h1 bg-red" />
+                <div className="br-100 mr1 w1 h1 bg-gold" />
+                <div className="br-100 mr1 w1 h1 bg-red" />
+            </div>
+            <div style={{ height: '512px' }}>
+                {children}
+            </div>
+        </div>
+    );
+};
+
+export default BrowserFrame;