With the command vendor/bin/robo map <target> you can map the extension folders into an existing Joomla installation. Each main extension folder is mapped individually with a symlink. Please note that for this to work in Windows, the command has to be run in an elevated command prompt.
The command vendor/bin/robo headers removes the file docblock from each php file in the source folder and adds in the header which has been set up in the jorobo.ini.
The command vendor/bin/robo bump replaces the string __DEPLOY_VERSION__ in all php files in the source folder with the version set in the jorobo.ini.
The command vendor/bin/robo asset:json will generate a joomla.asset.json file for every folder in the /media folder inside the source folder. If the file already exists, it will try to add new entries to it. It scans the css and js folders for css and script files and will try to add the minified version over the normal file, denoted with a .min.css or .min.js at the end. The joomla.asset.json is not necessarily complete, since you still have to add for example dependencies for your assets.