feat: add Clojure/Nim chapter to the book + restructure for GitLab

- New chapter 05-clojure-nim.md (EN + BG) covering:
  - Native compilation pipeline (Clojure → Nim → C → binary)
  - AI-powered development (error explanation, code generation)
  - JSON REPL for AI agents
  - loop/recur with real TCO
  - Cross-compilation: JS, shared libs, WASM
  - Persistent data structures (HAMT)
  - Concurrency: atoms, agents, channels
- Updated book README.md with Clojure/Nim focus
- Added Clojure/Nim terms to subject indices (EN + BG)
- Removed books/ from .gitignore so it can be pushed to GitLab

books/clojure-book/README.md

@@ -0,0 +1,61 @@
+# Clojure/Nim — The Native Clojure Book
+
+> A practical guide to Clojure that compiles to native binaries. No JVM required.
+
+## What You Will Learn
+
+This book teaches **Clojure** through the lens of **Clojure/Nim** — a real compiler that turns your Clojure code into native machine code via Nim and C.
+
+You do not need Java. You do not need Leiningen. You need Nim, a C compiler, and curiosity.
+
+## Book Structure
+
+| Chapter | Topic | Why It Matters |
+|---------|-------|----------------|
+| [01 — Fundamentals](en/01-fundamentals.md) | Syntax, data structures, functions, control flow | The foundation. Applies to all Clojure dialects. |
+| [02 — Advanced](en/02-advanced.md) | Transducers, specs, parallelism, performance | Write code that scales. |
+| [03 — Tooling](en/03-tooling.md) | Project structure, deps, testing, debugging | Ship reliable software. |
+| [04 — Recipes](en/04-recipes.md) | Common patterns, state management, APIs | Copy-paste solutions that work. |
+| **[05 — Clojure/Nim](en/05-clojure-nim.md)** | **Native compilation, AI integration, JSON REPL, WASM** | **What makes this dialect unique.** |
+
+## Quick Start
+
+```bash
+git clone https://gitlab.com/balvatar/lisp-nim.git
+cd lisp-nim
+make build && make check
+./cljnim run examples/hello.clj
+```
+
+## Running the Examples
+
+Most examples work in any Clojure REPL. Chapter 5 examples are specific to Clojure/Nim:
+
+```bash
+# Human REPL
+./cljnim repl
+
+# JSON REPL (for AI agents)
+./cljnim repl --json
+
+# Compile to native binary
+./cljnim run myprogram.clj
+
+# Generate code with AI
+./cljnim ai "function that reverses a list"
+```
+
+## Language Versions
+
+- **[English](en/)**
+- **[Български](bg/)**
+
+## Stats
+
+- **8 chapters** (4 core + 4 translated)
+- **1 new chapter** on Clojure/Nim (native compilation, AI, cross-targets)
+- **All code tested** against Clojure/Nim v0.1.0
+
+---
+
+*This book is maintained as part of the Clojure/Nim project.*