set up treefmt

treefmt.toml

@@ -0,0 +1,14 @@
+# One CLI to format the code tree - https://github.com/numtide/treefmt
+
+[global]
+# Glob patterns of files to exclude
+excludes = [".git/"]
+
+
+[formatter.nixfmt]
+# Formatter to run
+command = "nixfmt"
+# Command-line arguments for the command
+#options = []
+# Glob pattern of files to include
+includes = ["*.nix"]