chore: add envrc and shell.nix
diff --git a/.gitignore b/.gitignore
index 43686af..95e16ce 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,4 @@
 tests/output
 *.orig
 *.rej
+.direnv
\ No newline at end of file