Sri Lankan President Gotabaya Rajapaksa has announced he will step down after protesters stormed his official residence and set the prime minister's house on fire. Neither the PM nor the president were in the buildings at the time. Hundreds of thousands descended on the capital Colombo, calling for Rajapaksa to resign after months of protests over economic mismanagement. Rajapaksa will step down on July 13. PM Wickremesinghe has agreed to …