nerdfont.csv is a generated CSV that includes all of the Nerd Font icons and their description, as found on Nerd Font's Cheat Sheet website.

nerdfont.txt is a more readable version of that file

You will need to open the files with an editor that has a Nerd Font installed for.

A simple icon picker can be built with rofi (or dmenu) and the provided nerdfont.txt file. This picker will copy the icon to the clipboard (requires xsel installed)

cat "nerdfont.txt" | rofi -dmenu -i | awk '{print $1}' | xsel -i -b 

In wayland with fuzzel and wl-copy you can issue

 cat nerdfont.csv | fuzzel -d | gawk -F, '{printf $3}' | wl-copy 

A javascript file is included updateScript.js with instructions on how to generate nerdfont.csv and nerdfont.txt