Add FAQ regarding supported and non-supported protocols

[aputtu]

Users frequently asks if they can use SSH and Rsync over SSH, none of the options are supported.
Also, a number of support tickets indicates that the errors users receive are caused by trying to do ssh.
MiGrid instead offer SFTP and SSHFS.

This information should be included in the FAQ section, so users easily can get an overview of supported protocols, and also a list of common/expected protocols not support. Also point to ways of working around the limitations.

[jonasbardino]

Thanks @aputtu . For the record it should also be added in migrid-sync in order to show up in the Support pop-up on ERDA/MiGrid/SIF user pages.
In practice it is done by adding faq-entries accordion div entries in
https://github.com/ucphhpc/migrid-sync/blob/edge/state/wwwpublic/support-FQDN.html
for each production site FQDN. One entry for each language supported there (English and Danish currently).