Support other component file types

[lundmikkel]

We use Storybook when developing components. The switcher allows us to jump between all the other component files, but finding the Storybook files requires going to the explorer and selecting it.

Would it be possible to add the possibility to do custom extensions, that would allow us to add another shortcut for say Storybook files? I can see that both templates and style files have a setting for adding custom extensions, maybe the same idea could be used for custom file types.