Billionaire hedge fund manager Ken Griffin is moving his company’s headquarters from Chicago to Miami. In a note to employees Thursday, Griffin said his investment firm, Citadel, will relocate to new headquarters in Miami’s financial district after more than 30 years in Chicago. Citadel, which has about 1,000 employees in Chicago, will maintain an office in the city, but many are expected to shift with the corporate locus to the Sunshine State, where Griffin, a Florida native, recently moved with his family. “Chicago will continue to be important to the future of Citadel, as many of our collea…