Improoved AI Line for San Francisco GRiD HQ-Real 1.0 2020-06-01

I made a new AI-Line (fast_lane.ai) for San Francisco GRiD HQ-Real 1.0. It's not perfect as I tried to avoid that the AI cars cut the curves too much and bounce on the kerbs. In any case, they are faster almost 5 seconds in practice laps. just put on track folder/AI subfolder, make a backup copy of the original file before, in case you want to go back to the slower one.