DOCS-4412: Document sleep()

Signed-off-by: kay <kay.kim@10gen.com>

Author: i80and

source/includes/apiargs-method-sleep-param.yaml

@@ -0,0 +1,10 @@
+arg_name: param
+description: |
+  A duration in milliseconds.
+interface: method
+name: ms
+operation: sleep
+optional: false
+position: 1
+type: integer
+...

source/includes/ref-toc-method-native.yaml

@@ -10,6 +10,10 @@ name: ":method:`cd()`"
 file: /reference/method/cd
 description: "Changes the current working directory to the specified path."
 ---
+name: ":method:`sleep()`"
+file: /reference/method/sleep
+description: "Suspends the :program:`mongo` shell for a given period of time."
+---
 name: ":method:`copyDbpath()`"
 file: /reference/method/copyDbpath
 description: "Copies a local :setting:`~storage.dbPath`. For internal use."

source/reference/method/sleep.txt

@@ -0,0 +1,32 @@
+=======
+sleep()
+=======
+
+.. default-domain:: mongodb
+
+Definition
+----------
+
+.. method:: sleep(ms)
+
+   .. include:: /includes/apiargs/method-sleep-param.rst
+
+   :method:`sleep()` suspends a JavaScript execution context for a specified
+   number of milliseconds.
+
+Example
+-------
+
+Consider a low-priority bulk data import script. To avoid impacting other
+processes, you may suspend the shell after inserting each document, distributing
+the cost of insertion over a longer priod of time.
+
+The following example :program:`mongo` script will load a JSON file containing
+an array of documents, and save one element every 100 milliseconds.
+
+.. code-block:: javascript
+
+   JSON.parse(cat('users.json')).forEach(function(user) {
+       db.users.save(user);
+       sleep(100);
+   });