Ok, I find the hunspell directory portion not that confusing but anyway, I tried to make it more clear: https://gist.github.com/eht16/d2bfcb69a2d095fe6f5c3d427f8455fe
And also added a note about replacing hyphens by underscores. What do you think?
By the way, `C:\Programs\Geany\dict` is not a good choice to store custom data as it might be removed when Geany is upgraded. Better find a place outside of Geany's installation directory.