Combine all ingredients except for the avocado, yogurt, cilantro, and lime in a slow cooker. Cook on low for 5 to 6 hours or on high for 3 to 4 hours. Remove the chicken from the slow cooker and shred. Return to the cooker and cook on high for another 30 minutes.
Ladle into serving bowls. Optional: top with avocado, yogurt, cilantro, and a lime wedge.
*Nutritional information includes optional ingredients