feat: pdftohtml -> preserve paragraph leading indentation
From input file
with command /nix/store/5drv2qajbhb8qbr9pd2arq1b3p68l1aa-poppler-utils-21.03.0/bin/pdftohtml -enc UTF-8 ${pdf} ${outputdir}/myhtml
Output is
As we see, the paragraph leading indentation is not preserved
Suggestion:
add indentation in form of 3 whitespace, i.e.  
in the file (which in browser visible as
like this