add: GitHub Copilot Free to dev-tools

[Pratiyush]

What

Add GitHub Copilot Free to categories/dev-tools.md.

Details

• Service: GitHub Copilot (Free tier)
• Free tier: 2,000 code completions/mo, 50 chat/agent requests/mo, access to Haiku 4.5 and GPT-5 mini, Copilot CLI
• No credit card required
• Pricing page: https://github.com/features/copilot
• Verified: April 2026

GitHub Copilot Free has been available since late 2024 but is not yet listed in our dev-tools category. It's the most widely-used AI coding assistant and belongs alongside Cursor and Windsurf.

Category

categories/dev-tools.md