doku means documentation. You start to use it to write documentation.
If this documentation is tied to a product, you see that you have the text file and you start versioning them in git.
With combostrap, i do.
https://github.com/ComboStrap/website
You see that your IDE support markdown but not txt files, meaning that you can just search and navigate through the heading really, really quickly. You don’t need to open your browser or to have a toolbar to edit them.
Because you have now, your files in git, you got a lot of other git based editor software available.
Meaning that you can just change them on the go offline with a git mobile app.
If you use doku as a note taking tool, it’s really handy.