more informative error message for unsupported formats
When trying to import a file that uses a format that is not supported by Taguette, this error message pops up:
Error uploading file! Calibre returned 1
It would be great to have a more informative error message, possibly:
This format is not supported
And possibly a hint of which formats are supported, for example:
Taguette supports importing the following formats: .doc, .docx, .odt, .txt (etc.)
Using Taguette 0.9.2 in Firefox 83.0 on Ubuntu 18.04