Ubuntu 18.04 Repository

[ohdearaugustin]

I just tried to add the repository for the acmetool on Ubuntu 18.04. I use the following command for that:
$ sudo add-apt-repository ppa:hlandau/rhea

I got following error message:

The rhea PPA contains release packages for acmetool.
 More info: https://launchpad.net/~hlandau/+archive/ubuntu/rhea
Press [ENTER] to continue or Ctrl-c to cancel adding it.

Ign:1 http://ppa.launchpad.net/hlandau/rhea/ubuntu bionic InRelease
Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease
Hit:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
Err:5 http://ppa.launchpad.net/hlandau/rhea/ubuntu bionic Release
  404  Not Found [IP: 91.189.95.83 80]
Hit:6 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/hlandau/rhea/ubuntu bionic Release' does not have a Release file.                                             
N: Updating from such a repository can't be done securely, and is therefore disabled by default.                                                          
N: See apt-secure(8) manpage for repository creation and user configuration details.

So I assume there is no Release file yet for Ubuntu 18.04. I would like to request that feature.
Thanks.