export 'defaultTheme' was not found in 'bumbag'

[clementloridan]

Describe the bug

When I install bumbag and try the standalone theming. I got this error from my storybook:

`"export 'defaultTheme' was not found in 'bumbag'

1. Create as basic storybook
2. Install bumbag
3. Put <BumbagProvider theme={defaultTheme()} isStandalone />

Expected behavior

Not working like: https://bumbag.style/theming/#creating-your-own-global-theme-advanced

Screenshots

Device information (please complete the following information):

• Device: mac
• OS, version: MacOS, 10.15.5
• Browser, version: Chrome, 84.0.4147.89

Additional context

bumbag 1.3.19