Update tsconfig docs

[ghostdevv]

Please don't delete this checklist! Before submitting the PR, please make sure you do the following:

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with pnpm test and lint the project with pnpm lint and pnpm check

Changesets

• If your PR makes a change that should be noted in one or more packages' changelogs, generate a changeset by running pnpx changeset and following the prompts. All changesets should be patch until SvelteKit 1.0

Forgot to change this in #4791

[changeset-bot]

⚠️ No Changeset found

Latest commit: a0e0583

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[Rich-Harris]

Thank you, though I think this probably belong in the 'Others are required for SvelteKit to work properly' section rather than the 'generated programmatically based on your project configuration' section?

[ghostdevv]

I went back and forth on that quite a bit, if you think it does then I am all for it - SvelteKit works fine without it but the packaging will break unless you specifically change things

[ghostdevv]

Updated