mkdir ${XDG_CONFIG_HOME:-~/.config}/menus/

cp $prefix/etc/xdg/menus/xfce-applications.menu ${XDG_CONFIG_HOME:-~/.config}/menus

Did not proceed successfully.

But more easily:

some textfile > right click > open with other editor > select whichever you like > check always use this as default:

This was perfectly enough to set default editor.