Recommend Homebrew installation first in macOS getting started guide

[bhouston]

Recommend Homebrew installation first in macOS getting started guide

Problem

The current macOS getting started guide doesn't emphasize Homebrew as the recommended first step, even though it simplifies the installation of many developer tools including Git, GitHub CLI, and Node.js.

Proposed Solution

Restructure the macOS getting started guide to recommend installing Homebrew first, then use it to install the other required tools.

Implementation Details

1. Add a new section at the beginning of the prerequisites recommending Homebrew installation
2. Update the existing tool installation instructions to prioritize Homebrew-based installation methods
3. Show how Git, GitHub CLI, and NVM can all be easily installed via Homebrew
4. Keep alternative installation methods for users who prefer not to use Homebrew

Benefits

• Streamlines the setup process for macOS users
• Provides a consistent package management approach
• Makes future updates and maintenance easier for users

Acceptance Criteria

• Homebrew installation instructions added at the beginning of the macOS guide
• Instructions for installing Git, GitHub CLI, and NVM via Homebrew are clear
• The guide maintains alternative installation options for users who prefer not to use Homebrew
• Documentation builds and deploys successfully