github.copilot.chat.copilotCLI.addFileReference takes breadcrumbs keyboard shortcut and doesn't work

From https://github.com/microsoft/vscode-copilot-chat/pull/3529
This keybinding is used by breadcrumbs. What is this new command?

Also it doesn't seem to work
<img src="https://github.com/user-attachments/assets/88856810-a558-4a00-952b-c6e207606f4d" alt="Image" width="476" height="107">

