docs: Add comprehensive npm package documentation

Added complete guide for using LUMOS with JavaScript/TypeScript via npm.

Changes:
- New guide: guides/npm-package.md (comprehensive npm usage)
  - Installation options (global, project, npx)
  - CLI usage examples
  - Programmatic API reference
  - Build tool integration (Vite, Webpack, Rollup, esbuild)
  - CI/CD integration (GitHub Actions, GitLab, CircleCI)
  - Watch mode implementation
  - Monorepo usage (Nx, Turborepo)
  - TypeScript configuration
  - Comparison with Rust CLI
  - Troubleshooting section
  - Performance tips
  - Complete examples

- Updated: getting-started/installation.md
  - Added npm installation as first option
  - Clear separation between JS/TS and Rust installation
  - Link to detailed npm guide

Resolves getlumos/lumos#62 documentation requirements

Author: rz1989s

src/content/docs/getting-started/installation.md

@@ -3,7 +3,46 @@ title: Installation
 description: Install LUMOS CLI and start generating type-safe code for Solana
 ---
 
-## Prerequisites
+Choose your installation method based on your development environment:
+
+- **JavaScript/TypeScript** → [Install via npm](#install-via-npm-javascripttypescript)
+- **Rust/Anchor** → [Install via Cargo](#install-via-cargo-rustanchor)
+
+---
+
+## Install via npm (JavaScript/TypeScript)
+
+**No Rust required!** For JavaScript and TypeScript developers:
+
+```bash
+# Install globally
+npm install -g @getlumos/cli
+
+# Verify installation
+lumos --version
+# 0.1.0
+```
+
+**Or use directly with npx:**
+```bash
+npx @getlumos/cli generate schema.lumos
+```
+
+**Prerequisites:**
+- Node.js 16.0 or higher
+
+**Published Package:**
+- 📦 [@getlumos/cli](https://www.npmjs.com/package/@getlumos/cli) - npm package with WASM
+
+**Learn more:** [Using LUMOS with npm →](/guides/npm-package/)
+
+---
+
+## Install via Cargo (Rust/Anchor)
+
+For Rust and Anchor developers:
+
+### Prerequisites
 
 - **Rust 1.70 or higher**
 - **Cargo** package manager
@@ -17,9 +56,7 @@ rustc --version
 
 If you don't have Rust installed, visit [rustup.rs](https://rustup.rs)
 
----
-
-## Install from crates.io (Recommended)
+### Install from crates.io (Recommended)
 
 The fastest way to get started with LUMOS: