Documentation: Specify that AutoUpdate is a master switch for any update activities

[shaitanaleksander]

Problem
FileSystemWatcher is disabled when AutoUpdate is set to false. This behavior needs to be synchronized with the documentation.
documentation

[justadreamer]

AutoUpdate flag is a master switch, without it neither FileSystemWatcher nor polling is used. I don't think it is clearly stated in the doc page - we need to specify it.