Different git dir for git builtins

[MartyMcFlyInTheSky]

Is your feature request related to a problem? Please describe.
I'm using .myconfig in /home/myuser to manage my dotfiles. The problem is the telescope git builtins (e.g. require("telescope.builtin").git_bcommits() won't find this git directory by itself. So I can't use the full telescope git featureset to manage my dotfiles with my setup and that's a pitty.

Describe the solution you'd like
Gitsign lets the user define a git dir fallback like this:

        worktrees = {
            {
                toplevel = vim.env.HOME,
                gitdir = vim.env.HOME .. '/.myconfig'
            }
        }

I think the way it works is if no git dir is found in the current project, it will try these fallbacks. Would be nice to have something like this for telescope! Could be a picker opt, but I'd prefer if it was a default option though that I only have to specify once.

Describe alternatives you've considered
Renaming my dotfiles git directory, but the setup has proven very effective otherwise and I wouldn't want to be forced to do this honestly.

Additional context