At least 6,000 people, mostly mothers, according to organisers, staged a sit-in at a public park in the heart of Hong Kong’s business district on Friday night against the government’s controversial extradition bill.The crowd, dressed in black and holding carnations, filled up almost the entire open space of the 13,600 sq m Chater Garden in Central.“We’re just a group of ordinary mothers who love our children,” said barrister Linda Wong, mother of an eight-year-old son.During the three-hour…