Ten simple rules for measuring the impact of workshops by Sufi, S, Duckles, B, Simera, I, Nurmikko-Fuller, T, Bellis, L, Miah, W, Wilde, A, Nenadic, A, Silva, R, De Beyer, J, Struthers, C, Emsley, I, Philippe, O, Balzano, M, Coelho, S, Ford, H, Jones, C, Higgins, V