Global Nix configuration for applied to all workspaces
Add a nix file that is global and unique to a particular account which includes packages that a developer wants/needs in every workspace.
For example, neovim and its associated config is something I would want to use in every workspace, but other developers may not want that OR they may have an entirely different neovim config they want to use, making the dev.nix inside workspaces impractical.
While it is possible to manually edit every dev.nix with associated packages for each project. This, however, is inconvenient at best, and problematic at worst, especially if developers are collaborating on a repo and want the dev.nix state to be included in the repo but share differing opinions on things such as the neovim config mentioned above.