feat: rework to modular

modules/dev/rust.nix

@@ -0,0 +1,13 @@
+{ lib, pkgs, ... }:
+let
+  optionalPackage = path: lib.attrByPath path null pkgs;
+in
+{
+  home.packages = builtins.filter (pkg: pkg != null) [
+    pkgs.cargo
+    pkgs.rustc
+    (optionalPackage [ "rust-analyzer" ])
+    (optionalPackage [ "rustfmt" ])
+    (optionalPackage [ "clippy" ])
+  ];
+}