Install valadoc by entering the following commands in the terminal:
sudo apt update sudo apt install valadoc
Description:
API documentation generator for vala
Valadoc is a documentation generator for generating API documentation in HTML format from Vala source code. It can be used for *.vala and *.vapi files.
Homepage: https://wiki.gnome.org/Projects/Vala/
Version: 0.40.4-1
Section: universe/devel