chore: generate a rustler project

Signed-off-by: SphericalKat <amolele@gmail.com>

native/ketbin_utils_syntax/src/lib.rs

@@ -0,0 +1,6 @@
+#[rustler::nif]
+fn add(a: i64, b: i64) -> i64 {
+    a + b
+}
+
+rustler::init!("Elixir.Ketbin.Utils.Syntax", [add]);