Folder name could be more descriptive

[TylerLeonhardt]

Testing #8702

If I were to come back to this folder later, I wouldn't know what repo it came from (aside from the fact that the PR number is a huge number ;)).

I think it would be good to maybe put this under <folder-name>.worktrees or <folder-name>.worktree-pr-<number>

[TylerLeonhardt]

for context, I believe our existing worktree support in Copilot CLI puts them under the former so vscode.worktrees/copilot-worktree-<date>