MidnightLib for Minecraft 1.21.1, Fabric, there is no Condition static class in eu.midnightdust.lib.config.MidnightConfig, which is described in the documentation. Why does this library mention unimplemented features?

This feature is only available in MidnightLib 1.7.0 for 1.21.4 and higher.
I will eventually backport the latest version to MC 1.21.1, but I'm currently busy porting my mods to 1.21.6.