kcnhub: add swap note/warning

machines/kcnhub/hardware-configuration.nix

@@ -43,6 +43,8 @@
       options = [ "defaults" "pquota" ];
     };
 
+  # Note: Using swap on the SSD rapidly degrades its lifespan
+  # Especially large swaps that are consistently filled
   swapDevices = [ {
     device = "/swapfile";
     size = 125*1024;