Add missing 'type', 'defaultText' and 'literalExample' in module definitions

- add missing types in module definitions
- add missing 'defaultText' in module definitions
- wrap example with 'literalExample' where necessary in module definitions

nixos/modules/services/networking/lambdabot.nix

@@ -27,6 +27,7 @@ in
       package = mkOption {
         type = types.package;
         default = pkgs.lambdabot;
+        defaultText = "pkgs.lambdabot";
         description = "Used lambdabot package";
       };