   The child specification describes how the supervisor starts, shuts down,
   and restarts child processes.
 
-  The child specification contains 5 keys. The first two are required,
+  The child specification contains 6 keys. The first two are required,
   and the remaining ones are optional:
 
-    * `:id` - a value used to identify the child specification
+    * `:id` - any term used to identify the child specification
       internally by the supervisor; defaults to the given module.
       In the case of conflicting `:id` values, the supervisor will refuse
       to initialize and require explicit IDs. This key is required.

      restarts in transient mode, and linked processes exit with the same
      reason unless they're trapping exits

  Notice that supervisor that reached maximum restart intensity will exit with
  `:shutdown` reason. In this case the supervisor will only be restarted if its
  child specification was defined with the `:restart` option set to `:permanent`
  (the default).

      processes are terminated and then all child processes (including
      the terminated one) are restarted.

    * `:rest_for_one` - if a child process terminates, the terminated child
      process and the rest of the children started after it, are terminated and
      restarted.

  In the above, process termination refers to unsuccessful termination, which
  is determined by the `:restart` option.
