[DOCS] Add job groups to ML create/update job APIs (elastic/x-pack-elasticsearch#2290)

* [DOCS] Add job groups to ML create/update job APIs

* [DOCS] Fix ML update job API example

* [DOCS] Address feedback for ML create/update job APIs

Original commit: elastic/x-pack-elasticsearch@0e7bb47342

docs/en/rest-api/ml/jobresource.asciidoc

@@ -39,6 +39,10 @@ so do not set the `background_persist_interval` value too low.
   (string) If the job closed or failed, this is the time the job finished,
   otherwise it is `null`.
 
+`groups`::
+  (array of strings) A list of job groups.  A job can belong to no groups or
+  many. For example, `["group1", "group2"]`.
+
 `job_id`::
   (string) The unique identifier for the job.
 

docs/en/rest-api/ml/put-job.asciidoc

@@ -23,29 +23,32 @@ The create job API enables you to instantiate a job.
   See <<ml-analysisconfig, analysis configuration objects>>.
 
 `analysis_limits`::
-  Optionally specifies runtime limits for the job. See <<ml-apilimits,analysis limits>>.
+  (object) Specifies runtime limits for the job. See
+  <<ml-apilimits,analysis limits>>.
 
 `data_description` (required)::
   (object) Describes the format of the input data. This object is required, but
   it can be empty (`{}`). See <<ml-datadescription,data description objects>>.
 
 `description`::
-  (string) An optional description of the job.
+  (string) A description of the job.
+
+`groups`::
+  (array of strings) A list of job groups. See <<ml-job-resource>>.
 
 `model_plot`::
-  (object) This advanced configuration option stores model information along with the
-  results. This adds overhead to the performance of the system and 
-  is not feasible for jobs with many entities, see <<ml-apimodelplotconfig>>.
+  (object) This advanced configuration option stores model information along
+  with the results. This adds overhead to the performance of the system and is
+  not feasible for jobs with many entities, see <<ml-apimodelplotconfig>>.
 
 `model_snapshot_retention_days`::
   (long) The time in days that model snapshots are retained for the job.
-  Older snapshots are deleted. The default value is 1 day.
-  For more information about model snapshots, see <<ml-snapshot-resource>>.
+  Older snapshots are deleted. The default value is 1 day. For more information
+  about model snapshots, see <<ml-snapshot-resource>>.
 
 `results_index_name`::
-  (string) The name of the index in which to store the {ml} results.
-  The default value is `shared`, which corresponds to the index name
-  `.ml-anomalies-shared`.
+  (string) The name of the index in which to store the {ml} results. The default
+  value is `shared`, which corresponds to the index name `.ml-anomalies-shared`.
 
 
 ==== Authorization
@@ -90,8 +93,9 @@ When the job is created, you receive the following results:
 {
   "job_id": "it-ops-kpi",
   "job_type": "anomaly_detector",
+  "job_version": "7.0.0-alpha1",
   "description": "First simple job",
-  "create_time": 1491948238874,
+  "create_time": 1502832478794,
   "analysis_config": {
     "bucket_span": "5m",
     "latency": "0ms",

docs/en/rest-api/ml/update-job.asciidoc

@@ -30,8 +30,9 @@ each periodic persistence of the model. See <<ml-job-resource>>. | Yes
 
 |`custom_settings` |Contains custom meta data about the job. | No
 
-|`description` |An optional description of the job.
-See <<ml-job-resource>>. | No
+|`description` |A description of the job. See <<ml-job-resource>>. | No
+
+|`groups` |A list of job groups. See <<ml-job-resource>>. | No
 
 |`model_plot_config`: `enabled` |If true, enables calculation and storage of the
 model bounds for each entity that is being analyzed.
@@ -87,6 +88,7 @@ The following example updates the `it_ops_new_logs` job:
 POST _xpack/ml/anomaly_detectors/it_ops_new_logs/_update
 {
   "description":"An updated job",
+  "groups": ["group1","group2"],
   "model_plot_config": {
     "enabled": true
   },
@@ -116,9 +118,13 @@ information, including the updated property values. For example:
 {
   "job_id": "it_ops_new_logs",
   "job_type": "anomaly_detector",
+  "job_version": "7.0.0-alpha1",
+  "groups": [
+    "group1",
+    "group2"
+  ],
   "description": "An updated job",
-  "create_time": 1493678314204,
-  "finished_time": 1493678315850,
+  "create_time": 1502904685360,
   "analysis_config": {
     "bucket_span": "1800s",
     "categorization_field_name": "message",