refactor(pages): simplify landing page design

Remove gradients, marketing copy, and heavy visual chrome.
Replace with a plain, readable layout in the style of a classic
open-source project page. Flat color scheme, prose-first, code
blocks as the primary content, no promotional language.

Signed-off-by: Gokhankocmarli <gokhan.kocmarli@gmail.com>

Author: electricalgorithm