Install htmldoc-common by entering the following commands in the terminal:
sudo apt update sudo apt install htmldoc-common
Description:
Common arch-independent files for htmldoc
HTMLDOC is a program for writing documentation in HTML and producing indexed HTML, PostScript, or PDF output (with tables of contents). It supports most HTML 3.2 and some HTML 4.0 syntax, as well as GIF, JPEG, and PNG images. . This package contains the htmldoc files common to all architectures.
Homepage: https://www.msweet.org/htmldoc/
Version: 1.9.2-1
Section: universe/web