add rust template

templates/rust/.envrc

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+# ^ make editor happy
+
+#
+# Use https://direnv.net/ to automatically load the dev shell.
+#
+
+if ! has nix_direnv_version || ! nix_direnv_version 3.0.4; then
+  source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/3.0.4/direnvrc" "sha256-DzlYZ33mWF/Gs8DDeyjr8mnVmQGx7ASYqA5WlxwvBG4="
+fi  
+
+watch_file nix/**
+watch_file -- **/*.nix
+# Adding files to git includes them in a flake
+# But it is also a bit much reloading.
+# watch_file .git/index .git/HEAD
+use flake . --show-trace