Remove grml-live debs from deb.grml.org

[zeha]

We don't consume grml-live as a Debian package anywhere. We also expect grml-live users to customise the configs, and that they do so using a git branch. Thus, lets:

• find solution for the ISO changelog
• update grml-live.8.adoc section How do I deploy grml-live on a plain Debian installation? to point to git
• remove the grml-live(-grml) debs from deb.grml.org
• remove them from the packages.grml.org list
• keep building the debian package in github ci for verification

[zeha]

Turns out we do ship it in GRML_FULL!

[zeha]

We will need a solution for the grml-live changelogs