https://pentoo.github.io/ says the Kernel is 4.17.4
It points to pentoo.ch which says 2020 is the current release
It points to https://pentoo.ch/isos/Release/ as stable,
which is empty.
Is https://hub.docker.com/u/pentoolinux kept up to date? If so, you could link to it.
Keeping these up to date may help increase it adoption :-)