Git clone --shallow-submodules feature

[yw1ee]

I want to add a new option to the GIT-INIT program, and while searching some issues, I found this repository from tektoncd/pipeline#6417. I'm not sure if this is the right place to make such a request. If not, I would appreciate it if you could let me know.

The option I want to request is the --shallow-submodules option. I'm working on a repo with huge submodules, so it would be nice to have this option. If it's okay you, (though I've never used go before), it seems like a very simple fix, so I think I can add it myself. Let me know what you think. Thanks!