Also the file doesn't have to be at the root of the GitHub repo it can be from any URL/domain
> So for example, if you have a website for your project and have set the project URL to
https://www.myawseomepackage.com, we will look for the file at
https://www.myawseomepackage.com/umbraco-marketplace.json.
>
> Many people will link to a GitHub repository for this project URL, and if that's the case it works in a similar way. Here we will look for the umbraco-marketplace.json file in the root of the default branch of the repository, or a deeper link if that's what you have defined.