Average Days Between Orders

Shopify merchants want to know how often repeat customers come back. For each customer, consider their orders sorted by `order_date` (with `order_id` breaking ties on the same day) and compute the number of days between each order and the one before it. Return `customer_id`, `orders_count` (total orders) and `avg_days_between_orders` (average of those gaps, rounded to 2 decimals) for customers with at least 2 orders. Order the results by `customer_id` ascending.