update todo

src/runner.zig

@@ -73,8 +73,9 @@ pub const Runner = struct {
             return RunError.NoBMP;
         }
 
-        // TODO, copy load_path into a temporary file, then use that
+        // we don't copy load_path into a temporary file because we're already
-        // file to work on things.
+        // loading it under the SFM_READ mode, which won't cause any destructive
+        // operations on the file.
         self.image = try Image.open(self.allocator, load_path);
     }