On August 3rd, 2020, Deno changed their procedure to publish packages on deno.land/x:
https://deno.com/blog/registry2
In short, you need to add a webhook to this repository. Please go to https://deno.land/x and scroll to below the initial list of packages. There, click the "Add a module" button, it will guide you.
Afterwards you might need to publish a tag 1.0.1 for it to register, or republish (or repush, is that possible?) the 1.0.0 tag.
Thanks!