feat: add some links into module-system and advanced-topics

docs/advanced-topics/index.md

@@ -1,6 +1,5 @@
 ## Advanced Topics
 
-
 After becoming familiar with the NixOS, you can further explore Nix's three manuals and other docs to discover more ways to use it:
 
 - [Nix Reference Manual](https://nixos.org/manual/nix/stable/package-management/profiles.html): A guide to the Nix package manager, which mainly covers the design of the package manager and instructions for using it from the command line.
@@ -17,11 +16,13 @@ After becoming familiar with Flakes, you may want to try some advanced technique
 
 And many other useful community projects to explore, here are some of them:
 
+- [nixpak](https://github.com/nixpak/nixpak)
+- [nix-output-monitor](https://github.com/maralorn/nix-output-monitor)
 - [agenix](https://github.com/ryantm/agenix): secrets management
 - [colmena](https://github.com/zhaofengli/colmena): NixOS deployment tools
 - [nixos-generator](https://github.com/nix-community/nixos-generators): generate iso/qcow2/... from nixos configuration
 - [lanzaboote](https://github.com/nix-community/lanzaboote): enable secure boot for NixOS
 - [impermanence](https://github.com/nix-community/impermanence): used to make NixOS stateless, to imporve the reproduciability of NixOS system.
+- ...
 
-
-[digga]: https://github.com/divnix/digga
+[digga]: https://github.com/divnix/digga

docs/nixos-with-flakes/modularize-the-configuration.md

@@ -245,3 +245,8 @@ nix-repl> outputs.nixosConfigurations.nixos-test.config.environment.systemPackag
 So we can see that the order of `systemPackages` is `git -> curl -> default packages -> vim`, which is the same as the order we defined in `flake.nix`.
 
 > Though it's useless to adjust the order of `systemPackages`, it may be helpful at some other places...
+
+## References
+
+- [Nix modules: Improving Nix's discoverability and usability ](https://cfp.nixcon.org/nixcon2020/talk/K89WJY/)
+- [Module System - Nixpkgs](https://github.com/NixOS/nixpkgs/blob/nixos-unstable/doc/module-system/module-system.chapter.md)

docs/zh/advanced-topics/index.md

@@ -1,4 +1,3 @@
-
 ## 进阶玩法 {#advanced-topics}
 
 逐渐熟悉 Nix 这一套工具链后，可以进一步读一读 Nix 的三本手册，挖掘更多的玩法：
@@ -17,10 +16,13 @@
 
 以及其他许多实用的社区项目可探索，我比较关注的有这几个：
 
+- [nixpak](https://github.com/nixpak/nixpak)
+- [nix-output-monitor](https://github.com/maralorn/nix-output-monitor)
 - [agenix](https://github.com/ryantm/agenix): secrets 管理
 - [nixos-generator](https://github.com/nix-community/nixos-generators): 镜像生成工具，从 nixos 配置生成 iso/qcow2 等格式的镜像
 - [lanzaboote](https://github.com/nix-community/lanzaboote): 启用 secure boot
 - [impermanence](https://github.com/nix-community/impermanence): 用于配置无状态系统。可用它持久化你指定的文件或文件夹，同时再将 /home 目录挂载为 tmpfs 或者每次启动时用工具擦除一遍。这样所有不受 impermanence 管理的数据都将成为临时数据，如果它们导致了任何问题，重启下系统这些数据就全部还原到初始状态了！
 - [colmena](https://github.com/zhaofengli/colmena): NixOS 主机部署工具
+- ...
 
-[digga]: https://github.com/divnix/digga
+[digga]: https://github.com/divnix/digga

docs/zh/nixos-with-flakes/modularize-the-configuration.md

@@ -245,3 +245,9 @@ nix-repl> outputs.nixosConfigurations.nixos-test.config.environment.systemPackag
 能看到 `systemPackages` 的顺序是 `git -> curl -> default packages -> vim`，跟我们预期的一致。`lib.mkBefore [pkgs.git]` 确实是将 `git` 插入到了列表头，而 `lib.mkAfter [pkgs.vim]` 则是将 `vim` 插入到了列表尾。
 
 > 虽然单纯调整 `systemPackages` 的顺序没什么用，但是在其他地方可能会有用...
+
+
+## References
+
+- [Nix modules: Improving Nix's discoverability and usability ](https://cfp.nixcon.org/nixcon2020/talk/K89WJY/)
+- [Module System - Nixpkgs](https://github.com/NixOS/nixpkgs/blob/nixos-unstable/doc/module-system/module-system.chapter.md)