According to the Angular LTS plan, Angular 12
support ends in Nov 2022. A lot of code exists
to support Angular < 13 which increases the
maintenance effort and decreases the
contribution DX of framework/angular.
BREAKING CHANGE: Dropped support for Angular 12
Typescript-based svelte components did not generate docs correctly, and svelte-native stories were not possible.
## What I did
In the transition to 7.0, we neglected to load svelte options from `svelte.config.js` (and `svelteOptions` from storybook overrides) and pass them to the svelte docgen plugin, which means that svelte components written with typescript did not work correctly.
Also, while we brought over the `csfPlugin` for svelte, we never actually used it. So, svelte-native stories would be broken even if `@storybook/addon-svelte-csf` was added. The fix here is a bit of a temporary one, hopefully. It uses the same strategy from the 6.5 vite-builder, but it would be better if we could add vite-support to the addon directly, which I've suggested in https://github.com/storybookjs/addon-svelte-csf/issues/64#issuecomment-1266298532.
## How to test
Currently we do not have a svelte-vite typescript sandbox, nor do we have any svelte-native stories. But, I bootstrapped my own project, and copied over the `dist` folder from the `svelte-vite` framework in this branch, and confirmed that both docgen and svelte-native stories do not work without these changes, and do work with them.
Issue: https://github.com/storybookjs/builder-vite/issues/498
Closes https://github.com/storybookjs/storybook/pull/19245
## What I did
When we made the change in 7.0 to start using the user's `vite.config.js`, I made the (faulty) assumption that users would already have vite framework plugins (e.g. `@vitejs/plugin-react`) installed. But this isn't always true, for example, a project might just be a collection of components being exported, and there may not be an actual app.
So, this PR checks to see if the required framework plugin is already in the config, and if not, adds it. I created a utility function to check for the plugin, but ideally this would live in a `vite-core` instead of duplicated across each framework. This, combined with the duplication in https://github.com/storybookjs/storybook/pull/19216, makes me lean towards creating such a package. But, it can be done any time and these duplications cleaned up at that point, so I don't think it's a blocker.
## How to test
Create a sandbox, delete `vite.config.js`, and start storybook. Without this change there would be a crash, but it should work just fine now.
