✨ add git authentication section

[TanyaS08]

What the pull request does

Explain in a few words what the pull request does.

Type of change

Please indicate the relevant option(s)

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New tutorial page
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📖 Update to current tutorial page content
• 🔨 Backend change

Checklist

Please indicate the relevant option(s)

• New "pages" are added in _quarto.yml
• The website renders locally
  • you are able to execute quarto render without issues