Automated integration testing with a set of supported frameworks

[tonyketcham]

We can guarantee that Flatbread works with a set of frameworks by including some example integrations and ensuring they build in CI.

Frameworks we should test against:

• SvelteKit
• Next.js
• Remix
• Nuxt

[tonyketcham]

we might be able to do a hardlink on the config file between them so a change to one updates them all

[tonyketcham]

they should all share the same pool of content to avoid having to keep individual integration examples in sync

[tonyketcham]

#95 addresses the linking issue so that we have a single source of truth for all the examples