LTD is a command-line app for managing your Overland sites and applications. It comes with two built-in tasks for app and site scaffolding; additional tasks are added by a site's apps when LTD is run in an Overland installation. You'll need to refer to those packages for their tasks' use.
You'll want to install LTD globally for best results.
yarn global add ltd
ltd scaffold:site <my-site>
You can use
ltd scaffold:site to scaffold a new site. The command-line tool will ask you some questions and create a site for you.
ltd scaffold:app <my-app>
When creating a subapplication for a site, you can use
ltd scaffold:app to create a new app relative to the working directory. Then npm link the app to your site.