Directions in the Angular Style Guide read:
All of the app's code goes in a folder named src. All feature areas are in their own folder, with their own NgModule.
Angular Directory Structure is a talk, an application, and documentation detailing Angular application feature areas which may be applied piecemeal or as a whole to encourage proper module loading and logical folder structure while maintaining the direction of the style guide.
-- https://angular-folder-structure.readthedocs.io/en/latest/