Netbooting Manjaro, currently failing due to no memdisk support

This is basically a part 2 of the issue in the archived repository at Github (https://github.com/manjaro/manjaro-tools/issues/177).

I would kindly ask to either:

1. Restore PXE related settings, that were removed in a commit (42e0735b), two years ago.
2. Host a extracted ISO that's always up-to-date, when a new ISO gets published.
3. Publish a kernel we can use to netboot with.