By Jessica Dyer / Journal Staff Writer   A new apartment building is under construction on Central and 22nd. Albuquerque Mayor Tim Keller is proposing a bevy of zoning code changes to facilitate more multi-family housing and other housing options in Albuquerque. (Adolphe Pierre-Louis/Journal) Mayor Tim Keller is seeking what he calls "transformative" updates to Albuquerque's zoning code that could increase density in single-family home neighborhoods and relax some rules on apartment construction — all part of his effort to bolster housing development in New Mexico's largest city. Outlined in newly released legislation, the proposed changes would allow duplexes and...