As dev, I want `att_amend_desc()` without params to use config file by default

[statnmap]

Validation

• [ ] I can run directly att_amend_desc() and it will use the config file if exists, so that we do not have to change {fusen} behaviour
  Used on {attachment}} itself
  

• [ ] If not exist, it will create one with current parameters
  After deleting the file and run att_amend_desc()