Fish (and other shells) support

[Zopolis4]

I use fish as my exclusive shell in wsl, and have a variety of variables and functions set in config.fish that I frequently use in my git usage.

I would very much like not to have to port these over to bash, as they are in some cases impossible to port, so I was wondering if an option to use the default shell (set by chsh) or to set a specific shell could be added?