feat: rename project from nrd-sh to sukr

sukr = suckless + Rust. Minimal static site compiler.

- Update Cargo.toml name and description
- Update main.rs USAGE and doc comments
- Update AGENTS.md with new name, Tera architecture
- Create README.md with quick start guide

README.md

@@ -0,0 +1,59 @@
+# sukr
+
+**Minimal static site compiler — suckless, Rust, zero JS.**
+
+sukr transforms Markdown content into high-performance static HTML. No bloated runtimes, no unnecessary JavaScript, just clean output.
+
+## Features
+
+- **Build-time rendering** — Syntax highlighting via Tree-sitter, no client JS
+- **Tera templates** — Runtime customizable, no recompilation needed
+- **Convention over configuration** — Add sections by creating directories
+- **Monorepo support** — Multiple sites via `-c` flag
+
+## Quick Start
+
+```bash
+# Build
+cargo build --release
+
+# Run (uses ./site.toml)
+sukr
+
+# Custom config (monorepo)
+sukr -c sites/blog/site.toml
+
+# Help
+sukr --help
+```
+
+## Configuration
+
+Create `site.toml`:
+
+```toml
+title    = "My Site"
+author   = "Your Name"
+base_url = "https://example.com"
+
+[paths]  # All optional
+content   = "content"    # default
+output    = "public"     # default
+static    = "static"     # default
+templates = "templates"  # default
+```
+
+## Content Structure
+
+```
+content/
+├── _index.md          # Homepage
+├── about.md           # Standalone page → /about.html
+└── blog/
+    ├── _index.md      # Section index → /blog/index.html
+    └── my-post.md     # Post → /blog/my-post.html
+```
+
+## License
+
+MIT