“Freestyle Love Supreme” is an abundantly joyful and amusing freestyle, improvisational, hip-hop comedy show created by Thomas Kail, Anthony Veneziale, and Lin-Manuel Miranda.  A pricey enterprise given that it is, fundamentally, an improv show, lovers of wordplay will take great pleasure in the clever and witty rhymes that the rotating cast of rappers and beatboxers come up with on the spot based on audience suggestions, and cynics will see a well-marketed cash grab.