Rewrite _index.md as explanation-only — remove inline Quick
Start, add Learn More links. Move section discovery explanation
from features/sections.md into content-organization.md. Slim
sections.md to reference-only with cross-reference.
Normalize "Sukr" to "sukr" in architecture.md (4 instances).
Change site.toml title to lowercase. Fix template override
path from page/special.html to content/special.html. Update
copyright year to 2026.
Replace stale `cargo install sukr` with install-from-source.
Replace Step 4 dead-end with inline base.html, page.html,
and content/default.html templates. Add "View your site"
completion step. Improve Next Steps with reading-order context.
