doc: Clarify supported kubevirt formats (#1008)
doc: Clarify supported kubevirt formats (#1008)

Update the support matrix to clarify how files are handled when
content-type is kubevirt and to explicitly state that disk images should
not be encapsulated in a tar archive.

Signed-off-by: Adam Litke <ed9d9846a37e30d0259dba27fda9320ea24a6102@redhat.com>
kubevirt/containerized-data-importer,kubevirt/containerized-data-importer,kubevirt/containerized-data-importer