docs: fix link to changelog

[metonym]

Minor DX feedback. When looking for the link to the changelog in the svelte README, I was not expecting it to direct to the changelog for SvelteKit.

I think this is a typo since the link for SvelteKit points to the same location.

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• 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
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• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests and linting

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

[geoffrich]

Thanks for the catch!