make openpyxl more present/show the abilities to ao

[jensbri]

We only imported the xlsx file, we haven’t shown it; should do that in the future; we also have only one sheet in the xslx, we should show openpyxl to select one, then we should maybe write back to the Excel

Maybe add some video snipped showing how a file is opened in Excel. Saved. The dialogue where it complains that csv might result in loss (which is true: formatting is lost) but not true when it comes to the core data