feat: add Render support to adapter-auto

[pgull]

This adds zero-config deployment support for Render to adapter-auto.

Render exposes RENDER in the build environment and uses adapter-node for its SvelteKit template. This PR adds a Render detection mapping to adapter-node.

I've also updated the Zero-config deployments docs to list Render as a supported environment.

---

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[pkg-svelte-dev]

Install the latest version of @sveltejs/kit from a12620f:

pnpm add https://pkg.svelte.dev/@sveltejs/kit/c/a12620f73291fdd3abcce5f3b2e6fca1ae3cc595

Open in pkg.svelte.dev: https://pkg.svelte.dev/repos/kit/pr/16850

Note

This PR is from a fork. A maintainer must approve approve each commit before it can be built and installed.

[changeset-bot]

🦋 Changeset detected

Latest commit: a12620f

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

This PR includes changesets to release 1 package

Name	Type
@sveltejs/adapter-auto	Minor

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[teemingc]

Thanks for the PR. Do you mind rebasing this on the version-3 branch?

[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-16850-svelte.vercel.app/

[Rich-Harris]

thank you!