Move more things to the common host configuration

nix/hosts/common/users.nix

@@ -0,0 +1,20 @@
+{ username, ... }:
+
+{
+  users = {
+    users.${username} = {
+      isNormalUser = true;
+      description = "Oliver Davies";
+
+      extraGroups = [
+        "docker"
+        "networkmanager"
+        "wheel"
+      ];
+
+      packages = [ ];
+    };
+
+    defaultUserShell = "/etc/profiles/per-user/${username}/bin/zsh";
+  };
+}