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/continuous-integration/jenkins/default.nix

@@ -80,6 +80,7 @@ in {
 
       packages = mkOption {
         default = [ pkgs.stdenv pkgs.git pkgs.jdk config.programs.ssh.package pkgs.nix ];
+        defaultText = "[ pkgs.stdenv pkgs.git pkgs.jdk config.programs.ssh.package pkgs.nix ]";
         type = types.listOf types.package;
         description = ''
           Packages to add to PATH for the jenkins process.