Merge remote-tracking branch 'upstream/master' into 27377-preload-pipeline-entity27377-preload-pipeline-entity

* upstream/master: (2534 commits)
  Update VERSION to 9.3.0-pre
  Update CHANGELOG.md for 9.2.0
  removes unnecessary redundacy in usage ping doc
  Respect the typo as rubocop said
  Add a test to ensure this works on MySQL
  Change pipelines schedules help page path
  change domain to hostname in usage ping doc
  Fixes broken MySQL migration for retried
  Show password field mask while editing service settings
  Add notes for supported schedulers and cloud providers
  Move environment monitoring to environments doc
  Add docs for change of Cache/Artifact restore order"
  Avoid resource intensive login checks if password is not provided
  Change translation for 'coding' by 'desarrollo' for Spanish
  Add to docs: issues multiple assignees
  rename "Add emoji" and "Award emoji" to "Add reaction" where appropriate
  Add project and group notification settings info
  32570 Fix border-bottom for project activity tab
  Add users endpoint to frontend API class
  Rename users on mysql
  ...

1 files changed, 69 insertions, 12 deletions

diff --git a/doc/api/services.md b/doc/api/services.md
index 7d4779f1137..49b87a4228c 100644
--- a/doc/api/services.md
+++ b/doc/api/services.md
@@ -1,4 +1,4 @@
-# Services
+# Services API
 
 ## Asana
 
@@ -490,41 +490,98 @@ Remove all previously JIRA settings from a project.
 DELETE /projects/:id/services/jira
 ```
 
-## Mattermost Slash Commands
+## Slack slash commands
 
-Ability to receive slash commands from a Mattermost chat instance.
+Ability to receive slash commands from a Slack chat instance.
 
-### Create/Edit Mattermost Slash Command service
+### Get Slack slash command service settings
 
-Set Mattermost Slash Command for a project.
+Get Slack slash command service settings for a project.
 
 ```
-PUT /projects/:id/services/mattermost-slash-commands
+GET /projects/:id/services/slack-slash-commands
+```
+
+Example response:
+
+```json
+{
+  "id": 4,
+  "title": "Slack slash commands",
+  "created_at": "2017-06-27T05:51:39-07:00",
+  "updated_at": "2017-06-27T05:51:39-07:00",
+  "active": true,
+  "push_events": true,
+  "issues_events": true,
+  "merge_requests_events": true,
+  "tag_push_events": true,
+  "note_events": true,
+  "job_events": true,
+  "pipeline_events": true,
+  "properties": {
+    "token": "9koXpg98eAheJpvBs5tK"
+  }
+}
+```
+
+### Create/Edit Slack slash command service
+
+Set Slack slash command for a project.
+
+```
+PUT /projects/:id/services/slack-slash-commands
 ```
 
 Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `token` | string | yes | The Mattermost token |
+| `token` | string | yes | The Slack token |
 
 
-### Delete Mattermost Slash Command service
+### Delete Slack slash command service
 
-Delete Mattermost Slash Command service for a project.
+Delete Slack slash command service for a project.
 
 ```
-DELETE /projects/:id/services/mattermost-slash-commands
+DELETE /projects/:id/services/slack-slash-commands
 ```
 
-### Get Mattermost Slash Command service settings
+## Mattermost slash commands
+
+Ability to receive slash commands from a Mattermost chat instance.
+
+### Get Mattermost slash command service settings
 
-Get Mattermost Slash Command service settings for a project.
+Get Mattermost slash command service settings for a project.
 
 ```
 GET /projects/:id/services/mattermost-slash-commands
 ```
 
+### Create/Edit Mattermost slash command service
+
+Set Mattermost slash command for a project.
+
+```
+PUT /projects/:id/services/mattermost-slash-commands
+```
+
+Parameters:
+
+| Attribute | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `token` | string | yes | The Mattermost token |
+
+
+### Delete Mattermost slash command service
+
+Delete Mattermost slash command service for a project.
+
+```
+DELETE /projects/:id/services/mattermost-slash-commands
+```
+
 ## Pipeline-Emails
 
 Get emails for GitLab CI pipelines.