Storybook 6 support by default

[steveworkman]

👋 A snag list for things that I noticed when setting the required version to ^6.0.0 when invoking the plugin. I'll do my best to submit PRs for all of these

• The glob is now incorrect. It should have an @ before the (js|jsx....)
• Instead of installing all the dependencies, it can use the @storybook/essentials package
• This will enable the main.js file to be simpler, and it won't need the Vue/JSX hack
• The default stories should use <canvas> instead of <preview>
• Add documentation to MyButton.vue so that it can show off auto-documentation in <ArgsTable>

[pksunkara]

I fixed the glob after some testing