GAM Introduction updated

I just finnished giving a workshop on using Generalized Additive Mixed Models (GAMs) at Department of Linguistik of the University of Trier, thanks to the invitation of Jun.-Prof. Katharina Zahner-Ritter. Thanks to the feedback during the workshop, I realized that the GAM Introduction could need some updates. I have included some additional information on data curation, on multithreading and on how to use Quantile Generalized Additive Models (QGAMs). You can download the introduction from here or from my ressources page, where you can find additional ressources like an introduction to R programming, specifically how to preprocess your data for analysis.