OpenDocument Text export

[Deuchnord]

Is your feature request related to a problem? Please describe.
Kosmorro is currently already able to export the computation results to PDF, which is convenient for printing. But sometimes, we want to edit it to add our own notes, or even delete information we don't need.

Describe the solution you'd like
Make it possible to export to OpenDocument Text (.odt) format.

Describe alternatives you've considered
Annotate manually the PDF