Update Readme with information about Docker container #424

Job	Run time
Check DockerHub secrets exist	1s
test (debos-arch)	1m 32s
test (debos-bookworm)	1m 11s
test (debos-bullseye)	59s
test (debos-trixie)	1m 21s
Build Docker container	7m 45s
Run unit tests	2m 47s
recipes on nofakemachine	54s
debian (amd64) on nofakemachine	1m 40s
debian (arm64) on nofakemachine	3m 32s
debian (armhf) on nofakemachine	3m 44s
recipes on qemu	1m 36s
debian (amd64) on qemu	10m 12s
debian (arm64) on qemu	31m 55s
debian (armhf) on qemu	50m 41s
recipes on uml	51s
debian (amd64) on uml	4m 54s
debian (arm64) on uml	9m 42s
debian (armhf) on uml	21m 13s
arch on arch	13m 50s
partitioning on qemu	1m 13s
apertis on uml	7m 9s
partitioning on uml	1m 8s
allgreen	2s
Publish to GHCR	0s
Publish to DockerHub	0s
	2h 59m 52s

Provide feedback