Chinese tech giant Xiaomi is to begin selling its first electric car, the SU7, at the end of this month, Xiaomi founder Lei Jun announced on the Weibo social media network on Tuesday. Xiaomi shares rose in Hong Kong on the news that the electronics and software company was bringing cars of its own design to the market from March 28. Known in China primarily for smartphones and electrical appliances, Xiaomi announced three years ago that it was developing its own electric vehicle. The SU7, a four-door sedan being manufactured in cooperation with China’s state-owned BAIC vehicle manufacturer, wa…