nixos/slurm: Add man pages to wrapedSlurm

The nixos module adds a new derivation to
systemPackages to make sure that the binaries
get the generated config file. This derivation
did not contain the man pages so far.
Activating the module now makes the man pages
available in the system environment.

nixos/modules/services/computing/slurm/slurm.nix

@@ -204,6 +204,9 @@ in
           EOT
             chmod +x "$wrappername"
           done
+
+          mkdir -p $out/share
+          ln -s ${getBin cfg.package}/share/man $out/share/man
         '';
       };