Reference to a file is not serialized

[daumantas-versockas]

Steps to reproduce

1. Choose a page where table contains images, i.e. https://en.m.wikipedia.org/wiki/List_of_equipment_of_the_United_States_Army
2. Copy and paste url to wikitable2csv web application
3. Image section of a table is mostly empty

[Aschroet]

Would be very helpful to have this feature.