In some cases you just use composer to create a project in which you pull in your packages. In most of my website I use this. It would be cool to be able to use the deploy script section to update the site. Right now you must use a repository in order to use a deploy script.
Also, if you are going to implement this option, you need to show the deploy webhook somewhere. It's now located in the repository tab. Maybe add a new tab called "Deployment" or something. Or adding the deploy webhook to settings / manage tab