docs: Update README.md Windows instructions

[matthewpereira]

Through user testing I observed developers struggling to get Auth0 CLI working properly on Windows machines. I've updated the install instructions (Powershell in particular) to provide the instructions that have so far been successful.

🔧 Changes

• Unify Linux and macOS instructions, with brew listed first and cURL instructions listed next.
• Separate Powershell instructions into separate instructions
• Provide more explicit instructions on how to set PATH and HOME environment variables successfully
• Remind users to restart Powershell so that it will use latest environment variables
• Formatted tips with > [!TIP] syntax

🔬 Testing

1. Follow instructions verbatim on a Windows PC, or
2. Witness a user doing Add github CI #1

📝 Checklist

• [N/A] All new/changed/fixed functionality is covered by tests (or N/A)
• [N/A] I have added documentation for all new/changed functionality (or N/A)

[matthewpereira]

Closing this to resolve problems with EMU and signed commits. Replaced by #1077