envrc: watch rust.nix shell file; vscode: fix treefmt usage

templates/default/.envrc

@@ -3,6 +3,7 @@
 
 # Automatically reload when this file changes
 watch_file ./nix/devshells/default.nix
+watch_file ./nix/devshells/rust.nix
 watch_file ./nix/*.nix
 
 # Load `nix develop`

templates/default/.vscode/settings.json

@@ -11,15 +11,18 @@
     // settings for 'nil' LSP
     "nil": {
       "formatting": {
-        "command": ["treefmt-nix", "--stdin", "neverexists.nix"]
+        "command": ["treefmt", "--stdin", "neverexists.nix"]
       }
     }
   },
-
   "[rust]": {
     "editor.formatOnSave": true,
     "editor.defaultFormatter": "rust-lang.rust-analyzer"
   },
   "rust-analyzer.interpret.tests": true,
-  "rust-analyzer.cfg.setTest": true
+  "rust-analyzer.cfg.setTest": true,
+
+  // FIXME(upstream): without these treefmt-vscode will look for a config
+  "treefmt.command": "treefmt",
+  "treefmt.config": ""
 }