Add basic layout and configuration in theme.config.ts

[AbraaoAlves]

Add default blog theme layout.

Follow the tutorial below:
https://nextra.site/docs/blog-theme/start#create-the-root-layout

This issue should be finish just after #7

[AbraaoAlves]

Maybe we can configure initial blog theme like this one:

https://codehike.org/blog/the-curse-of-markdown

[RodrigoNet0]

I followed the UI proposal with a dark theme and neon blue and green elements to maintain the tech identity. The sections implemented so far:

✅ Navbar with links (Home, Posts, About, Contact)

✅ Hero section with a title, subtitle, and call-to-action button

✅ "Latest Posts" section with 3 simulated cards

Screen

@AbraaoAlves