[docs] Update the snippet to use latest Next.js template

[siriwatknp]

closes #45922

• Change the snippet from diff to tsx so that users can copy and paste to their project

---

• I have followed (at least) the PR section of the contributing guide.

[siriwatknp]

@mnajdova diff is hard for copy pasting so I changed to tsx. Do you think this is a better experience? If yes, I will update the App Router guide too.

[oliviertassinari]

Between https://deploy-preview-45946--material-ui.netlify.app/material-ui/integrations/nextjs/#configuration-2 and https://deploy-preview-45944--material-ui.netlify.app/material-ui/integrations/nextjs/#configuration-2 It feels like the diff UX wins with a long shot for my use case: I can't copy and paste the whole demo, I have ton of custom logic in my _document.js, but with a diff, I know what to look at.

The best solution is to have CLI that applies the changes, like Shadcn does, but that's a different story #39588 and #40062.

[siriwatknp]

The best solution is to have CLI that applies the changes, like Shadcn does, but that's a different story #39588 and #40062.

As you said, it's a different story.

For this PR, the change display the smallest snippet to demonstrate the integration. I think it's better than the previous one.

[mui-bot]

Netlify deploy preview

• docs/data/material/integrations/nextjs/nextjs.md

Bundle size report

No bundle size changes (Toolpad)
No bundle size changes

Generated by 🚫 dangerJS against 412ffdc