doc: add tutorial for end users
Closes T2676
work in progressm with only the initial part about mounting and blobs for now
Migrated from D4296 (view on Phabricator)
Staging instance, all changes can be removed at any time
Closes T2676
work in progressm with only the initial part about mounting and blobs for now
Migrated from D4296 (view on Phabricator)