Caramelized Onion Pizza with Goat Cheese and Turkey Sausage

Name: Caramelized Onion Pizza with Goat Cheese and Turkey Sausage
Ingredients: 1 envelope active dry yeast; 1 1/2 to 2 cups all-purpose flour; 1 cup whole-wheat flour; 1 1/2 teaspoons salt, plus more to taste; 5 tablespoons extra-virgin olive oil, plus more for bowl, baking sheets, and brushing; 2 tablespoons unsalted butter; 8 medium red onions, sliced into 1/4-inch rounds (3 pounds); 10 to 12 garlic cloves, peeled; 2 tablespoons balsamic vinegar; 2 teaspoons sugar; 1/4 teaspoon freshly ground pepper; 8 ounces turkey sausage; 5 ounces goat cheese; 2 teaspoons chopped fresh herbs (such as rosemary, parsley, thyme)