SAN FRANCISCO :Microsoft on Thursday said it plans to build a second massive artificial intelligence data center in Wisconsin, bringing its spending in the state to more than $7 billion. The new project will join a $3.3 billion data center in Mount Pleasant in the southeastern corner of the state, announced last year. Microsoft said Thursday that the initial data center remains on track to open next year and will employ about 500 people at its peak, expanding to about 800 once the second data