feature(cluster): start pacemaker config

devices/cluster/modules/pacemaker.nix

@@ -0,0 +1,17 @@
+{nixpkgs-pacemaker, ...}: let
+  pacemakerPath = "services/cluster/pacemaker/default.nix";
+in {
+  # FIXME: https://github.com/NixOS/nixpkgs/pull/208298
+  nixpkgs.overlays = [
+    (final: prev: {
+      inherit
+        (nixpkgs-pacemaker.legacyPackages.x86_64-linux)
+        pacemaker
+        ocf-resource-agents
+        ;
+    })
+  ];
+
+  disabledModules = [pacemakerPath];
+  import = ["${nixpkgs-pacemaker}/nixos/modules/${pacemakerPath}"];
+}