Den gibt es schon 
nur siehst Du ihn vermutlich nicht weil Du noch im /homeassistant Ordner bist und den File Editor noch nicht so eingestellt hast.
Wobei ich selber den Netzwerkspeicher auch noch nie als “Freigabe”-Ort verwendet habe.
Backup
This will become a target. You can use it when creating an automatic or manual backup. The first storage you add of this type becomes your new default target. If you want to change the default target, check out the documentation below.
Media
A new directory with the name you gave your network storage will be created under /media. This directory can be accessed by Home Assistant and add-ons.
Share
A new directory with the name you gave your network storage will be created under /share. This directory can be accessed by Home Assistant and add-ons.
VG Jim