fix(parser)

parser used to work depending on opening parenthesis and therefore
parsed e.g. `(if 0 (list 1 2 3) 1)` as two seperate expressions, thus
the example would print:
1
(1 2 3)

Now fixed by using a stack for parenthesis

main.c

@@ -51,7 +51,11 @@ int main(int argc, char **argv) {
 #endif
 
     Nodes evaluated = {0};
-    int ret = eval(&result, &scopes, &evaluated);
+    int ret = eval(result, &scopes, &evaluated);
+    if (ret != 0) {
+        return 1;
+    }
+
     nob_da_foreach(Node, node, &evaluated) {
         node_print(*node);
         printf("\n");