docs: improved installation and migration guides

docs/getting-started/index.md

@@ -2,14 +2,22 @@
 title: Getting Started
 ---
 
-Welcome to Quartz! This section will walk you through setting up your digital garden from scratch.
+This guide walks you through setting up Quartz from scratch. If you already ran the [[index#🪴 Get Started|quickstart]] on the home page, you can skip ahead to whichever step you're on.
 
-## Setup
+## Prerequisites
 
-1. **[[installation|Installation]]** — Clone Quartz, create your repository, and push your first sync
-2. **[[authoring-content|Authoring Content]]** — Write and organize your notes in the `content` folder
-3. **[[build|Building]]** — Preview your site locally with `npx quartz build --serve`
-4. **[[hosting|Hosting]]** — Deploy your Quartz site to the web
+- **[Node.js](https://nodejs.org/) v22 or later** (run `node -v` to check)
+- **npm v10.9.2 or later** (bundled with Node — run `npm -v` to check)
+- **[Git](https://git-scm.com/)** (run `git -v` to check)
+
+## Setup Steps
+
+Follow these in order:
+
+1. **[[installation|Installation]]** — Clone Quartz, install dependencies, run the setup wizard (`npx quartz create`), install plugins, and preview your site locally
+2. **[[authoring-content|Authoring Content]]** — Write and organize your Markdown notes in the `content/` folder
+3. **[[installation#Setting Up Your GitHub Repository|Push to GitHub]]** — Create a repository and push your site with `npx quartz sync`
+4. **[[hosting|Deploy]]** — Host your site for free on GitHub Pages, Cloudflare, Netlify, or Vercel
 
 ## Upgrading & Migrating