Bug: --text-page-separator option ignores empty pages

[sokolgeo]

Hi, since your very kind implementation of the --text-page-separator in #44, there seems to be a bug in the current implementation.

Empty pages seems to be completely ignored by the --text-page-separator output. This makes the implementation essentially useless for the purpose, because you can not simply attach this text output page-by-page as invisible search layer to pdf printout as pages in pdf and txt will not match each other after the first empty page in the document.

Minimal example attached: 20241109_144728.zip

It's a three page note with pages 1 and 3 containing "x" and page 2 is empty. When running supernote-tool convert -t txt -a --text-page-separator='-- my unique page separator --' 20241109_144728.note output.txt the resulting output is:

x
-- my unique page separator --
x

I believe the correct implementation should produce instead:

x
-- my unique page separator --
-- my unique page separator --
x

Could you please look into this?