Peel the onion and cut it in half lengthwise. Slice each half crosswise into thin half-moons. Transfer the onion slices to a container with a lid (like a quart-sized mason jar or Tupperware container). Add the vinegar, water, salt, sugar, hot sauce, and herbs. Seal the container and give it a good shake. Transfer the onions to the refrigerator and marinate for at least 2 hours, but preferably overnight. The onions will keep for 1 month.