Merge branch 'docs/jira-service-api' into 'master'

Add all endoints to JIRA service API documentation

## What does this MR do?

Add missing API endpoints to the JIRA service.

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ee/issues/440

See merge request !7122

doc/api/services.md

@@ -451,43 +451,49 @@ GET /projects/:id/services/irker
 
 ## JIRA
 
-Jira issue tracker
+JIRA issue tracker.
+
+### Get JIRA service settings
+
+Get JIRA service settings for a project.
+
+```
+GET /projects/:id/services/jira
+```
 
 ### Create/Edit JIRA service
 
 Set JIRA service for a project.
 
-> Setting `project_url`, `issues_url` and `new_issue_url` will allow a user to easily navigate to the Jira issue tracker. See the [integration doc](http://docs.gitlab.com/ce/integration/external-issue-tracker.html) for details.  Support for referencing commits and automatic closing of Jira issues directly from GitLab is [available in GitLab EE.](http://docs.gitlab.com/ee/integration/jira.html)
+>**Note:**
+Setting `project_url`, `issues_url` and `new_issue_url` will allow a user to
+easily navigate to the JIRA issue tracker. See the [integration doc][jira-doc]
+for details.
 
 ```
 PUT /projects/:id/services/jira
 ```
 
-Parameters:
-
-- `new_issue_url` (**required**) - New Issue url
-- `project_url` (**required**) - Project url
-- `issues_url` (**required**) - Issue url
-- `description` (optional) - Jira issue tracker
-- `username` (optional) - Jira username
-- `password` (optional) - Jira password
+| Attribute | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `active`        | boolean| no  | Enable/disable the JIRA service. |
+| `project_url`   | string | yes | The URL to the JIRA project which is being linked to this GitLab project. It is of the form: `https://<jira_host_url>/issues/?jql=project=<jira_project>`. |
+| `issues_url`    | string | yes | The URL to the JIRA project issues overview for the project that is linked to this GitLab project. It is of the form: `https://<jira_host_url>/browse/:id`. Leave `:id` as-is, it gets replaced by GitLab at runtime.|
+| `new_issue_url` | string | yes | This is the URL to create a new issue in JIRA for the project linked to this GitLab project, and it is of the form: `https://<jira_host_url>/secure/CreateIssue.jspa` |
+| `api_url`       | string | yes | The base URL of the JIRA API. It may be omitted, in which case GitLab will automatically use API version `2` based on the `project url`. It is of the form: `https://<jira_host_url>/rest/api/2`. |
+| `description`   | string | no  | A name for the issue tracker. |
+| `username`      | string | no  | The username of the user created to be used with GitLab/JIRA. |
+| `password`      | string | no  | The password of the user created to be used with GitLab/JIRA. |
+| `jira_issue_transition_id` | string | no | The ID of a transition that moves issues to a closed state. You can find this number under the JIRA workflow administration (**Administration > Issues > Workflows**) by selecting **View** under **Operations** of the desired workflow of your project. The ID of each state can be found inside the parenthesis of each transition name under the **Transitions (id)** column ([see screenshot][trans]). By default, this ID is set to `2`. |
 
 ### Delete JIRA service
 
-Delete JIRA service for a project.
+Remove all previously JIRA settings from a project.
 
 ```
 DELETE /projects/:id/services/jira
 ```
 
-### Get JIRA service settings
-
-Get JIRA service settings for a project.
-
-```
-GET /projects/:id/services/jira
-```
-
 ## PivotalTracker
 
 Project Management Software (Source Commits Endpoint)
@@ -662,3 +668,5 @@ Get JetBrains TeamCity CI service settings for a project.
 ```
 GET /projects/:id/services/teamcity
 ```
+
+[jira-doc]: ../project_services/jira.md