This instance will be upgraded to Heptapod 0.31.0 (final) on 2022-05-24 at 14:00 UTC+2 (a few minutes of down time)

Makefile: automatically generate dependencies and rules

Greatly inspired by https://philpep.org/blog/a-makefile-for-your-dockerfiles

This open the way to automatically update variants. However this is not part of
this series.
1 job for topic/default/split-make in 15 seconds