Niki Mendez is no student of architecture, but she knows what she likes. And that includes the conversion of a towering parking deck built in the 1920′s into a 250-unit apartment building in the Newark neighborhood where she works for a state agency. “I think it’s actually beautiful,” said Mendez, 46, of Newark, pausing on her way home on a recent afternoon in front of the Washington Street building in the city’s University Heights neighborhood. “It’s an improvement, and it just makes the community look a lot nicer.” The 18-story Newark Urby, a conversion that began in 2020, leased its first a…