Added keyd to override caps with LWin

modules/common/keyd.nix

@@ -0,0 +1,26 @@
+{
+  config,
+  pkgs,
+  ...
+}: {
+  services.keyd = {
+    enable = true;
+    keyboards = {
+      # The name is just the name of the configuration file, it does not really matter
+      default = {
+        ids = ["*"]; # what goes into the [id] section, here we select all keyboards
+        # Everything but the ID section:
+        settings = {
+          # The main layer, if you choose to declare it in Nix
+          main = {
+            capslock = "layer(LWin)"; # you might need to also enclose the key in quotes if it contains non-alphabetical symbols
+          };
+          otherlayer = {};
+        };
+        extraConfig = ''
+          # put here any extra-config, e.g. you can copy/paste here directly a configuration, just remove the ids part
+        '';
+      };
+    };
+  };
+}