All my config is under ./modules. Use the module and customize what you want.
Take a look at ./configuration.nix.example. The
example also can be taken as a reference for home.nix when importing
./modules/user/home.nix into home-manager modules.
local is used for private or local files. Other files' path can be used as
well with git update-index --assume-unchanged <file-list> or
git update-index --skip-worktree <file-list>.