Refactor(build-clan): rename to lib/modules

This is a preparation for moving everything into clan, to make it all one module evaluation

lib/modules/eval-docs.nix

@@ -0,0 +1,21 @@
+{
+  pkgs,
+  lib,
+  clanLib,
+}:
+let
+  eval = lib.evalModules {
+    class = "nixos";
+    modules = [
+      (lib.modules.importApply ./interface.nix { inherit clanLib; })
+    ];
+  };
+  evalDocs = pkgs.nixosOptionsDoc {
+    options = eval.options;
+    warningsAreErrors = false;
+  };
+in
+{
+  inherit (evalDocs) optionsJSON optionsNix;
+  inherit eval;
+}