To uninstall debian-timeline just follow these instructions.
/debian/stretch/main///install/index.html Web-based timeline of the Debian Project Debian 9.0 web 38
sudo apt-get remove debian-timeline
Which will remove just the debian-timeline package itself.
sudo apt-get remove --auto-remove debian-timeline
This will remove the debian-timeline package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for debian-timeline then this will work.
sudo apt-get purge debian-timeline
Or similarly, like this debian-timeline
sudo apt-get purge --auto-remove debian-timeline
|Maintainer||Debian publicity team
|Description||Web-based timeline of the Debian Project|