fix: path missing in first item of "On this page" component for Docs site

[SrGeneroso]

Add some missing properties for the correct creation of href for the first items of "On this page" component of the Sveltekit Docs. Currently doesn't create that reference in the first item and prevent navigation to the top of the page.

More info on issue

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🥹Junior dev PR

I'm not sure how to do that. I've done it manually and I hope is done properly.

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[PuruVJ]

LGTM! Thanks