emacs support for new languages + dependencies

modules/dev/rust.nix

@@ -0,0 +1,19 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+{
+  options.my.dev.rust.enable = lib.mkEnableOption "enable";
+  config = lib.mkIf config.my.dev.rust.enable {
+    users.users.jawz.packages = builtins.attrValues {
+      inherit (pkgs)
+        cargo # Rust package manager
+        rust-analyzer # Language server for Rust
+        clippy # Linter for Rust
+        rustfmt # Formatter for Rust code
+        ;
+    };
+  };
+}