Todo list for fixes in future releases

[e-alfred]

Here are some issues that should be fixed in some minor versions in the future:

• [ ] new README GIF (?)
• [ ] Security testing
• [ ] testing on Nextcloud 20
• [ ] fix warnings in build script for Webpack/NPM
• [ ] Add warning that not all external storages are supported (SMB works, SFTP sometimes, Webdav times out #92, Openstack/Amazon S3/FTP untested)