* Amending docs on security privileges required for Watcher
Previously, the watcher_user and watcher_admin roles did not exist so we documented the actual security privileges necessary. Now that these roles exist and encapsulate the security privileges, we update the documentation to refer to the roles instead.
* Breaking up sentences. Putting main content up front.
* Include triggered watches as well
* Emphasize read-only operations
Original commit: elastic/x-pack-elasticsearch@720d84557c
Deb Adair
Lisa Cawley
Shaunak Kashyap