Either I didn't express myself clearly, or I didn't understand something.
(Installed Sigil and got stuck).
Let me rephrase my problem.
My works are stored nicely on my hard disk, all of them TXT files.
I'm quite happy with it
However, it would be nice to be able to tag the files, rate them, mark unfinished files and so on. Hence the ebook software.
At the same time, I need to be able to edit the files, not only store and manage them.
Calibre would be great, but when I edit the files in Calibre, they don't get changed in the source folder (the one from which I exported them).
That's why I try to look for some solution...
I could also try different software (free and one that can read Polish fonts).
Any ideas?