docs(v2): revise "writing docs" (#1561)

* Revise doc on writing docs

* More work on docs doc

* misc(v2): tweak docs

* misc(v2): fix typo

website/components/BrowserWindow/index.js

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import React from 'react';
+import classnames from 'classnames';
+
+import styles from './styles.module.css';
+
+function BrowserWindow({children, minHeight, url}) {
+  return (
+    <div className={styles.container} style={{minHeight}}>
+      <div className={styles.row}>
+        <div className={classnames(styles.column, styles.left)}>
+          <span className={styles.dot} style={{background: '#ED594A'}} />
+          <span className={styles.dot} style={{background: '#FDD800'}} />
+          <span className={styles.dot} style={{background: '#5AC05A'}} />
+        </div>
+        <div className={classnames(styles.column, styles.middle)}>
+          <input disabled={true} type="text" value={url} readOnly />
+        </div>
+        <div className={classnames(styles.column, styles.right)}>
+          <div style={{float: 'right'}}>
+            <span className={styles.bar} />
+            <span className={styles.bar} />
+            <span className={styles.bar} />
+          </div>
+        </div>
+      </div>
+
+      <div className={styles.content}>{children}</div>
+    </div>
+  );
+}
+
+export default BrowserWindow;