feat: add yt-dlp plugin

[duhow]

Summary

Description:

• Tool repo URL: https://github.com/yt-dlp/yt-dlp
• Plugin repo URL: https://github.com/duhow/asdf-yt-dlp

Additional notes

Since this is a fork of youtube-dl, I placed yt-dlp next to it in the README list.

Checklist

• Format with scripts/format.bash
• Test locally with scripts/test_plugin.bash --file plugins/<your_new_plugin_name>
• Your plugin CI tests are green
  • Tip: use the plugin_test action from asdf-actions in your plugin CI

[jthegedus]

Thanks