Actress Rashmika Mandanna joined co-star Sidharth Malhotra to begin shooting for her debut Hindi film "Mission Majnu" in Lucknow on Friday. Taking to her Instagram, Rashmika posted the update on Friday and captioned it as, "Mission Majnu Day 1". It is a story set in an era that saw intriguing developments in the world of espionage and Rashmika will lend …