TAIPEI—Taiwan raised its coronavirus alert level on Saturday in the capital, Taipei, and the surrounding city, bringing curbs for a period of two weeks that will shut many venues and restrict gatherings in the wake of 180 new domestic infections. Masks are to be worn outdoors for the first time, as the government encourages work and study from home, shutting cinemas and entertainment spots, while limiting gatherings of families and friends to five indoors and 10 outdoors. Taipei’s government has already ordered bars, nightclubs, and similar venues to shut. Health Minister Chen Shih-chung said a “level of risk” in certain hot spots, such as Taipei’s gritty Wanhua district, had spurred the decision to raise the alert level. “Only by doing this can infections be dealt with and controlled,” he told reporters. Taipei Mayor Ko Wen-je urged people to stay home as much as possible, adding that schools teaching should move …