add an option to choose VBF jets selection method
- Current three methods are available: BDT, maximum mjj and pT-sorting
- Validation plots: https://sizhang.web.cern.ch/sizhang/PublicPlots/ATLASresults/non-resonant-HHbbyy/Plots/VBFJets/MR818_methods/
Edited by Sijing Zhang