Add short description explaining how SFTP ext storage class works.
Add short description explaining how SFTP ext storage class works.

pixelipo/server,owncloud/core,cernbox/core,IljaN/core,owncloud/core,bluelml/core,phil-davis/core,Ardinis/server,sharidas/core,pmattern/server,whitekiba/server,michaelletzgus/nextcloud-server,Ardinis/server,pmattern/server,michaelletzgus/nextcloud-server,xx621998xx/server,pollopolea/core,IljaN/core,pollopolea/core,whitekiba/server,owncloud/core,owncloud/core,IljaN/core,endsguy/server,bluelml/core,andreas-p/nextcloud-server,nextcloud/server,xx621998xx/server,andreas-p/nextcloud-server,lrytz/core,xx621998xx/server,pollopolea/core,cernbox/core,pmattern/server,nextcloud/server,whitekiba/server,pollopolea/core,jbicha/server,andreas-p/nextcloud-server,jbicha/server,jbicha/server,cernbox/core,xx621998xx/server,nextcloud/server,whitekiba/server,owncloud/core,bluelml/core,IljaN/core,pixelipo/server,cernbox/core,pixelipo/server,cernbox/core,Ardinis/server,whitekiba/server,lrytz/core,Ardinis/server,IljaN/core,bluelml/core,pollopolea/core,jbicha/server,endsguy/server,endsguy/server,sharidas/core,endsguy/server,lrytz/core,pixelipo/server,lrytz/core,pixelipo/server,Ardinis/server,michaelletzgus/nextcloud-server,andreas-p/nextcloud-server,bluelml/core,sharidas/core,andreas-p/nextcloud-server,sharidas/core,jbicha/server,endsguy/server,sharidas/core,michaelletzgus/nextcloud-server,xx621998xx/server,pmattern/server,pmattern/server,lrytz/core,nextcloud/server