Gluten-Free Pad Thai

8 onces uncooked rice noodles (5mm) 1 Tablespoon rice wine vinegar 1 1/2 Tablespoons gluten-free fish sauce 1 to 2 Tablespoons fresh lemon juice 1 Tablespoon ketchup 2 teaspoons sugar 1/4 teaspoon red pepper flakes 1 Tablespoon vegetable oil 1 boneless skinless chicken breast, chopped 2 green onions, thinly sliced 2 cloves garlic, minced 3…