[Enhancement] Adding support for the new "Chat with Copilot" button

[blakegearin]

GitHub has added a new "Chat with Copilot" button to the navigation bar. This userscript should...

• Add "Copilot" text in the "Happy Medium" configuration

• Remove the button in the "Old School" configuration

• For custom configuration...

  • Add the ability to hide the button

  • Add the ability of adding custom button text

  • Add the ability of replacing the button's icon with another

[blakegearin]

First two were added in https://github.com/blakegearin/github-custom-global-navigation/releases/tag/1.6.0

Adding support for custom configuration is more finicky and requires more manual testing, but I hope to get around to it in 2025.