Use Ladle instead of Storybook

[bensmithett]

https://ladle.dev/

Storybook is obviously more "industry standard", but I did have an issue with the Vite builder (storybookjs/builder-vite#234 - apparently fixed, I need to test this). Vite feels a bit more like a second class citizen in Storybook's Webpack world.

Ladle is new though, too early to say if it'll have staying power...

[bensmithett]

I spiked this and I like it. Just need to solve tajo/ladle#207 then I think I'll make the switch. The Vite-nativeness takes away lots of headaches.

[bensmithett]

OK, problem solved and I'm making the switch.

• It's Vite-native. Everything just works with zero config and no special plugins. I get to delete a bunch of code and dependencies.
• Unblocks adopting MDX 2! Doesn't work in project that depends on MDX 2 storybookjs/builder-vite#234
• It has a much leaner feature set than Storybook (I hope it stays that way)