feature-request: Allow for the repo map to be made from the Git Submodules in the project as well

[monksy]

Currently Aider does not allow for git submodules to be included in the repo map for usage.

I would like for it to be able to explore submodules as well.

[dwash96]

I don't use sub modules myself, but I think the changes in 0.96.10 to make the .cecli.ignore file equivalent to specifying a full custom .gitignore file combined with subtree-only: false should allow this to be possible