add tests.

test/test_main.c

@@ -0,0 +1,11 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+int main(int argc, char **argv) {
+  // return 1;
+  return 0;
+}