WIP: Standarderror

Hi Dariya, I know there are many rules and I also know that I don´t necessarily follow all of them when things worked fine. In the end, it´s a process that went on parallel to this analysis. I want to learn to produce better code and adapt, but I would also like to get this paper out of the door :)

A note on the data. All data sets I use for the analysis are available on SACO (https://saco.csic.es/index.php/apps/files/?dir=/csic-echo/data/ENSE-EDAD-EDUCATION-DIFFERENTIALS&fileid=8696499).

Let me know when you don´t understand what´s happening or how things work (I am sure, you will be fine).

And no need to look at this before Monday