feat(docs): create sukr documentation site with fixes

Self-documenting docs site built with sukr itself (dogfooding):

Core changes:
- Rename package from nrd-sh to sukr
- Move personal site to sites/nrd.sh/
- Update AGENTS.md and README.md

Documentation site (docs/):
- Add site.toml with sukr.io base URL
- Create docs-specific templates with sidebar navigation
- Add dark theme CSS with syntax highlighting colors
- Document all features: templates, sections, syntax highlighting,
  mermaid diagrams, and LaTeX math rendering

Bug fixes:
- Render individual pages for all sections (not just blog type)
- Add #[source] error chaining for Tera template errors
- Print full error chain in main() for better debugging

src/main.rs

@@ -142,15 +142,13 @@ fn run(config_path: &Path) -> Result<()> {
             }
         }
 
-        // Render individual content pages (for blog posts)
-        if section.section_type == "blog" {
-            for item in &items {
-                eprintln!("  processing: {}", item.slug);
-                let html_body = render::markdown_to_html(&item.body);
-                let page_path = format!("/{}", item.output_path(&content_dir).display());
-                let html = engine.render_content(item, &html_body, &page_path, &config, &nav)?;
-                write_output(&output_dir, &content_dir, item, html)?;
-            }
+        // Render individual content pages for all sections
+        for item in &items {
+            eprintln!("  processing: {}", item.slug);
+            let html_body = render::markdown_to_html(&item.body);
+            let page_path = format!("/{}", item.output_path(&content_dir).display());
+            let html = engine.render_content(item, &html_body, &page_path, &config, &nav)?;
+            write_output(&output_dir, &content_dir, item, html)?;
         }
 
         // Render section index