addDisks method
Add disks for FileStorage and disk(), on top of the defaults
(local, documents, cache, temp and assets); a disk with the
same name as a default replaces it. defaultDisk names the disk used
when none is given.
Implementation
void addDisks(Map<String, DiskConfig> disks, {String? defaultDisk}) {
FileStorage.configure(disks: disks, defaultDisk: defaultDisk);
}