Various changes

- `hs` host
  - cam subdomain behind reverse proxy
  - dynamic dns updater script
- `pc` host
  - ext4 instead of btrfs
  - ca-derivations experimental feature
- nix from unstable channel (2.8)
- cura from stable (unstable went broken)
- Emacs
  - company-nixos-options
  - helm-nixos-options
  - nix-modeline
  - disable format hook on save for nix mode
- nix from master (only in overlay, not used)
- bat (alias for cat)
- batman (alias for batman)
- disabled weird extra options for nix I couldn't even remember of
- Fira Code for sway/waybar
- New plain style for waybar

hosts/pc/configuration.nix

@@ -38,7 +38,13 @@
   fileSystems."/" =
     {
       device = "/dev/disk/by-label/nixos";
-      fsType = "btrfs";
+      fsType = "ext4";
+    };
+  
+  fileSystems."/home" =
+    {
+      device = "/dev/disk/by-label/home";
+      fsType = "ext4";
     };
 
   swapDevices =
@@ -49,15 +55,16 @@
       automatic = true;
       options = "--delete-older-than 3d";
     };
+    # package = pkgs.nixFromMaster;
+    package = pkgs.nix; # currently from unstable through an overlay
+    extraOptions = ''
+      experimental-features = ca-derivations 
+    '';
   };
 
-
   networking.firewall = {
     enable = true;
     allowPing = true;
-    allowedTCPPorts = [
-      5900 # vnc
-    ];
   };
 
   # TODO: disable, only for playing