profiles/core: add comments for each option

profiles/core/default.nix

@@ -2,6 +2,7 @@
 let inherit (lib) fileContents;
 in
 {
+  # Sets nrdxp.cachix.org binary cache which just speeds up some builds
   imports = [ ../cachix ];
 
   config = {
@@ -86,18 +87,18 @@ in
     nix = {
       package = pkgs.nix-dram;
 
+      # Improve nix store disk usage
       autoOptimiseStore = true;
-
       gc.automatic = true;
-
       optimise.automatic = true;
 
+      # Prevents impurities in builds
       useSandbox = true;
 
-      allowedUsers = [ "@wheel" ];
-
+      # give root and @wheel special privileges with nix
       trustedUsers = [ "root" "@wheel" ];
 
+      # Generally useful nix option defaults
       extraOptions = ''
         min-free = 536870912
         keep-outputs = true
@@ -108,14 +109,7 @@ in
       '';
     };
 
-    system.autoUpgrade.enable = true;
-
-    # For rage encryption, all hosts need a ssh key pair
-    services.openssh = {
-      enable = true;
-      openFirewall = lib.mkDefault false;
-    };
-
+    # Service that makes Out of Memory Killer more effective
     services.earlyoom.enable = true;
 
     boot.supportedFilesystems = [ "ntfs" ];