Peaks with plots

[anastassiavybornova]

• replaced 04_peaks notebook by its new (almost finalized) version
• reorganized /plots subfolder
• the plots produced by the 04_peak notebook might want to see some adjustments to make them look nicer

[martinfleis]

• not sure if the peak on the right has not necessarily be higher - might be worth exploring Auckland
• can we save results as JSON or something like that instead of a pickle? pickle is a reproducibility nightmare