anchor.diff:  
   [[schedule-scheduler]]
   When you add a watch, {watcher} immediately registers its trigger with the
  -appropriate trigger engine. Watches that have a `schedule` trigger are 
  -registered with the `scheduler` trigger engine. 
  -
  -The scheduler tracks time and triggers watches according to their schedules. 
  +appropriate trigger engine. Watches that have a `schedule` trigger are
  +registered with the `scheduler` trigger engine.
  +
  +The scheduler tracks time and triggers watches according to their schedules.
   On each node, that contains one of the `.watches` shards, a scheduler, that is
   bound to the watcher lifecycle runs. Even though all primaries and replicas are
   taken into account, when a watch is triggered, watcher also ensures, that each
  
positive.code: registered with the appropriate trigger engine, and executed according
  to its configured trigger.
  
  You can also set a watch to the _inactive_ state. Inactive watches are not 
  registered with a trigger engine and can never be triggered.
  
  To set a watch to the inactive state when you create it, set the 
  <<watcher-api-put-watch-active-state, `active`>> parameter to _inactive_. 
  To deactivate an existing watch, use the <<watcher-api-deactivate-watch, D
  eactivate Watch API>>. To reactivate an inactive watch, use the 
  <<watcher-api-activate-watch, Activate Watch API>>.
  
  NOTE:   You can use the <<watcher-api-execute-watch, Execute Watch API>> to
  
negative.code: engines use a separate thread pool from the one used to execute watches.
  
  When a watch is triggered, {watcher} queues it up for execution. A `watch_record`
  document is created and added to the watch history and the watch's status is set
  to `awaits_execution`.
  
  When execution starts, {watcher} creates a watch execution context for the watch.
  The execution context provides scripts and templates with access to the watch
  metadata, payload, watch ID, execution time, and trigger information. For more
  information, see <<watch-execution-context, Watch Execution Context>>.
  
  During the execution process, {watcher}:
  