feat(devShells): shell for NixOS configuration development

devShells/nixos.nix

@@ -0,0 +1,25 @@
+# SkyOS
+/**
+  Development shell with tools needed for configuration editing
+*/
+pkgs: {
+  /**
+    tool for managing __runtime__ secrets. See [sops-nix](https://github.com/mic92/sops-nix) for more info
+  */
+  packages.sops = pkgs.sops;
+  /**
+    tool for managing __eval time__ secrets.
+
+    In near future, it's going to be replaced by my own project which uses `sops` instead of bare `age`
+  */
+  packages.git-agecrypt = pkgs.git-agecrypt;
+
+  /**
+    tool for generating documentation from comments in .nix files
+  */
+  packages.nixdoc = pkgs.nixdoc;
+  /**
+    tool for generating book from md files made by `nixdoc`
+  */
+  packages.mdbook = pkgs.mdbook;
+}