Volkswagen (VW) says it will invest up to $5bn (£3.94bn) in Tesla rival Rivian.The deal creates a joint venture that will allow the German car making giant and the US-based electric vehicle (EV) maker to share technology.Rivian shares jumped by around 50% after the announcement. The tie-up comes as competition intensifies between EV makers and Western countries impose tariffs imports of Chinese EVs.Under the agreement, VW said it will initially invest $1bn in the electric truck and SUV maker, with another $4bn to be put into the company by 2026.Founded in 2009, Rivian has not yet posted…