(Reuters) – The nationwide shortage of baby formula has prompted the United States to temporarily allow foreign imports from other suppliers, while reaching a deal with Abbott Laboratories on steps to resume production at its Michigan plant. Top infant formula makers, including Reckitt Benckiser, Nestle and Danone SA, are also ramping up supplies to the country. Here is a timeline on how the crisis unfolded and the measures being taken to resolve it: Feb. 17 Abbott recalls dozens of types of powdered baby formulas, including Similac, Alimentum and EleCare, made at its Sturgis, Michigan plant a…