docs: link tsconfig sections to kit config

[theetrain]

Sometimes folks may not be aware that changes to top-level tsconfig.json configs such as include will override instead of merge with the generated .svelte-kit/tsconfig.json via extends.

This PR links to the typscript config option in svelte.config.js next to other relevant sections to help boost awareness.

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-14026-svelte.vercel.app/

[benmccann]

This is great! Thank you!

If you're up for it, I think it'd also be helpful to include an example in /docs/kit/configuration#typescript

[eltigerchino]

Thank you! I didn't even know this was a thing until now. Do you know if the paths passed through this setting should be relative to the location of the generated tsconfig? (I think having the example Ben mentioned would help here)

An out-of-scope random thought: wonder if it's worth typing the typescript.config setting so that it's not just Record<string, any>. Does typescript have a type for the tsconfig?