Janet W. Lee In today’s TV news roundup, NBC will air “Decision 2020: Election Special,” and PBS will premiere “Ledisi Live: A Tribute to Nina Simone.”Tonight, NBC will air “Decision 2020: Election Special” live from 8 to 11 p.m. ET. The station’s East Coast affiliates will have the option to air the special from 7 to 8 p.m., while West Coast stations will air local coverage from 8 to 9 p.m., then “The Wall” from 9 to 10 p.m. and “Dateline NBC” from 10 to 11 p.m. The season finale of “American