PARIS—Air France’s new airline Joon unveiled seven new destinations as it operated its first flights from Paris on Dec. 1. The airline, which is one strand of the Air France-KLM group’s strategic turnaround plan to improve profitability, aims to target millennial travelers. Although the company has said it is not a low-cost carrier, it plans to keep its cost base low.   The carrier said Joon, which is starting operations with flights from Paris Charles de Gaulle ...