Documentation: Drawer Natigation Example Error

**Describe the bug**
From the Documentation, the example Drawer Natigation displays an error on the website itself:

https://docs.nativebase.io/building-drawer-navigation

**To Reproduce**
Steps to reproduce the behavior:
1. Go to https://docs.nativebase.io/building-drawer-navigation
2. Click on Example
3. Scroll down to Example
4. See error

**Expected behavior**
To see the example.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Platform**
NativeBase version: Last