Reorganize imports

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/configs/user/options.nix

@@ -0,0 +1,28 @@
+{ lib, ... }:
+let
+  userOptions =
+    with lib;
+    with types;
+    { config, ... }:
+    {
+      options = {
+        email = mkOption {
+          type = nullOr str;
+          description = "Email address of the user.";
+        };
+
+        fullName = mkOption {
+          type = nullOr str;
+          description = "Full name of the user.";
+        };
+      };
+    };
+in
+{
+  options =
+    with lib;
+    with types;
+    {
+      users.users = mkOption { type = attrsOf (submodule userOptions); };
+    };
+}