Add .html support

[natemoo-re]

Changes

• Adds .html support to Astro!
• .html files can be used as components or pages
• .html files accept content for any slot elements (default or named)
• .html files can opt-out of slot overloading by using the is:inline attribute
• Referencing relative assets from an .html file is not supported, assets must be in public/
  • Use an .astro file with imports if you need this!
• .html files treat script and style elements as is:inline.
  • Use an .astro file if you need advanced script/style behavior.
• .html files treat self-closing elements according to the HTML specification (/> is ignored.)
  • Use an .astro file if you want self-closing element support for every element.

Testing

Test coverage added

Docs

TODO

[changeset-bot]

🦋 Changeset detected

Latest commit: 41820f9

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 12 packages

Name	Type
astro	Patch
@e2e/astro-component	Patch
@e2e/error-react-spectrum	Patch
@e2e/error-sass	Patch
@e2e/errors	Patch
@e2e/lit-component	Patch
@e2e/preact-component	Patch
@e2e/react-component	Patch
@e2e/solid-component	Patch
@e2e/svelte-component	Patch
@e2e/e2e-tailwindcss	Patch
@e2e/ts-resolution	Patch

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[Princesseuh]

For TypeScript purpose, an accessible module declaration will be needed so there's no editor errors when importing .html file, ex:

declare module "*.html" {
  const content: string;
  export default content;
}

It can be inside astro-env.d.ts if you don't mind there being no type errors even when the integration isn't installed, otherwise it might require a change in the language server to load types from integrations in Astro files (without requiring the user to explicitly add it to types inside their tsconfig.json)