Add foreman/overmind requirement to Getting Started guides (#1897)

New developers following the Getting Started guides encounter the "can't
find executable foreman" error when running ./bin/dev. This commit adds
clear documentation about this prerequisite in both the Quick Start and
Using React on Rails guides.

Changes:
- Add foreman/overmind to Prerequisites section in quick-start.md
- Add installation instructions before bin/dev command in quick-start.md
- Add note with installation info in using-react-on-rails.md
- Include links to detailed installation guides for both tools
- Emphasize global installation requirement for foreman

This improves the developer onboarding experience by surfacing this
requirement before developers encounter errors.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <[email protected]>

Author: justin808

docs/getting-started/quick-start.md

@@ -13,6 +13,7 @@ Before starting, make sure you have:
 - **Rails 7+** application (Rails 5.2+ supported)
 - **Ruby 3.0+** (required)
 - **Node.js 20+** and **Yarn**
+- **Foreman or Overmind** (for running `bin/dev`)
 - **Basic familiarity** with React and Rails
 
 > 💡 **Don't have a Rails app?** Run `rails new my_react_app` first.
@@ -42,6 +43,11 @@ Take a look at the files created by the generator.
 
 ## 🎯 Step 2: Start the Development Server (1 minute)
 
+> **Note:** Ensure you have `overmind` or `foreman` installed to run `bin/dev`.
+>
+> - **overmind**: `brew install overmind` (macOS) or see [installation guide](https://github.com/DarthSim/overmind#installation)
+> - **foreman**: `gem install foreman` (install globally, not in your project bundle - [details](https://github.com/ddollar/foreman/wiki/Don't-Bundle-Foreman))
+
 Start both Rails and the Webpack dev server:
 
 ```bash

docs/getting-started/using-react-on-rails.md

@@ -149,6 +149,8 @@ The generator creates `bin/dev` for starting both:
 - Rails server (port 3000)
 - Webpack dev server (for hot reloading)
 
+> **Note:** You need `overmind` or `foreman` installed to run `bin/dev`. Install with `brew install overmind` (macOS) or `gem install foreman` (globally). See the [Quick Start Guide](./quick-start.md#-step-2-start-the-development-server-1-minute) for detailed installation instructions.
+
 ---
 
 ## Render-Functions and RailsContext