Buttons are rendering with empty "type"

[mejiaj]

Buttons are compiling with type="", they should be using type="button". This is affecting our documentation. For example Buttons

[mahoneycm]

It looks like this is happening because the type attribute isn't being defined in the components json file. On storybook, we're defining the attribute as a control with a default value, but it doesn't get compiled with webpack.

I've created a solution on #5247 which sets the default button.json type="button". Everything seems to be working appropriately! Let me know if you see any implications of this solution that I may be missing