R-Studio Tutorial: Adding a custom legend to a plot with multiple elements

In this #tutorial we will discover together how to add a legend to a plot with multiple elements. For the original tutorial on how to create multiple lines in one plot go to this video: https://www.youtube.com/watch?v=ZY2TUTeZ-7o&t=2s For all videos related to GGPlot check out this playlist: https://www.youtube.com/playlist?list=PLz70pddaPJ-Y250Ri9c1oXYfzXby2e_uh