fix indentation in several nixos option descriptions

nixos/modules/config/gnu.nix

···
     gnu = mkOption {
       type = types.bool;
       default = false;
-      description =
-        '' When enabled, GNU software is chosen by default whenever a there is
-           a choice between GNU and non-GNU software (e.g., GNU lsh
-           vs. OpenSSH).
-        '';
+      description = ''
+        When enabled, GNU software is chosen by default whenever a there is
+        a choice between GNU and non-GNU software (e.g., GNU lsh
+        vs. OpenSSH).
+      '';
     };
   };
 

nixos/modules/config/i18n.nix

···
         default = with pkgs.kbdKeymaps; [ dvp neo ];
         defaultText = ''with pkgs.kbdKeymaps; [ dvp neo ]'';
         description = ''
-	  List of additional packages that provide console fonts, keymaps and
+          List of additional packages that provide console fonts, keymaps and
           other resources.
         '';
       };

nixos/modules/programs/mosh.nix

···
 in
 {
   options.programs.mosh = {
-      enable = mkOption {
-	description = ''
-	  Whether to enable mosh. Note, this will open ports in your firewall!
-	'';
-        default = false;
-	example = true;
-	type = lib.types.bool;
-      };
+    enable = mkOption {
+      description = ''
+        Whether to enable mosh. Note, this will open ports in your firewall!
+      '';
+      default = false;
+      example = true;
+      type = lib.types.bool;
+    };
   };
 
   config = mkIf cfg.enable {

nixos/modules/services/networking/wireguard.nix

···
         default = null;
         example = "rVXs/Ni9tu3oDBLS4hOyAUAa1qTWVA3loR8eL20os3I=";
         type = with types; nullOr str;
-        description = ''base64 preshared key generated by wg genpsk. Optional,
-        and may be omitted. This option adds an additional layer of
-        symmetric-key cryptography to be mixed into the already existing
-        public-key  cryptography, for post-quantum resistance.'';
+        description = ''
+          base64 preshared key generated by wg genpsk. Optional,
+          and may be omitted. This option adds an additional layer of
+          symmetric-key cryptography to be mixed into the already existing
+          public-key  cryptography, for post-quantum resistance.
+        '';
       };
 
       listenPort = mkOption {
         default = null;
         type = with types; nullOr int;
         example = 51820;
-        description = ''16-bit port for listening. Optional; if not specified,
-        automatically generated based on interface name.'';
+        description = ''
+          16-bit port for listening. Optional; if not specified,
+          automatically generated based on interface name.
+        '';
       };
 
       preSetup = mkOption {
···
         ''];
         default = [];
         type = with types; listOf str;
-        description = ''A list of commands called at the start of the interface
-        setup.'';
+        description = ''
+          A list of commands called at the start of the interface setup.
+        '';
       };
 
       postSetup = mkOption {

nixos/modules/system/boot/loader/generations-dir/generations-dir.nix

···
       copyKernels = mkOption {
         default = false;
         type = types.bool;
-        description = "
+        description = ''
           Whether copy the necessary boot files into /boot, so
           /nix/store is not needed by the boot loader.
-        ";
+        '';
       };
 
     };