Port some EE API docs to CE

The following EE files had small differences with their CE counterpart
so they have been ported to CE:

- doc/api/boards.md
- doc/api/discussions.md
- doc/api/notes.md
- doc/api/resource_label_events.md
- doc/api/services.md

1 files changed, 129 insertions, 1 deletions

diff --git a/doc/api/notes.md b/doc/api/notes.md
index dfde80c6441..c09129c22d4 100644
--- a/doc/api/notes.md
+++ b/doc/api/notes.md
@@ -1,6 +1,11 @@
 # Notes API
 
-Notes are comments on snippets, issues or merge requests.
+Notes are comments on:
+
+- Snippets
+- Issues
+- Merge requests
+- Epics **[ULTIMATE]**
 
 This includes system notes, which are notes about changes to the object (for example, when a milestone changes, there will be a corresponding system note). Label notes are not part of this API, but recorded as separate events in [resource label events](resource_label_events.md).
 
@@ -390,3 +395,126 @@ Parameters:
 ```bash
 curl --request DELETE --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/merge_requests/7/notes/1602
 ```
+
+## Epics **[ULTIMATE]**
+
+### List all epic notes
+
+Gets a list of all notes for a single epic. Epic notes are comments users can post to an epic.
+
+```
+GET /groups/:id/epics/:epic_id/notes
+GET /groups/:id/epics/:epic_id/notes?sort=asc&order_by=updated_at
+```
+
+| Attribute           | Type             | Required   | Description |
+| ------------------- | ---------------- | ---------- | ----------- |
+| `id`                | integer/string   | yes        | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |
+| `epic_id`           | integer          | yes        | The ID of a group epic |
+| `sort`              | string           | no         | Return epic notes sorted in `asc` or `desc` order. Default is `desc` |
+| `order_by`          | string           | no         | Return epic notes ordered by `created_at` or `updated_at` fields. Default is `created_at` |
+
+```bash
+curl --request GET --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/groups/5/epics/11/notes
+```
+
+### Get single epic note
+
+Returns a single note for a given epic.
+
+```
+GET /groups/:id/epics/:epic_id/notes/:note_id
+```
+
+Parameters:
+
+| Attribute | Type           | Required | Description |
+| --------- | -------------- | -------- | ----------- |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |
+| `epic_id` | integer | yes  | The ID of an epic |
+| `note_id` | integer | yes  | The ID of a note |
+
+```json
+{
+  "id": 52,
+  "title": "Epic",
+  "file_name": "epic.rb",
+  "author": {
+    "id": 1,
+    "username": "pipin",
+    "email": "admin@example.com",
+    "name": "Pip",
+    "state": "active",
+    "created_at": "2013-09-30T13:46:01Z"
+  },
+  "expires_at": null,
+  "updated_at": "2013-10-02T07:34:20Z",
+  "created_at": "2013-10-02T07:34:20Z"
+}
+```
+
+```bash
+curl --request GET --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/groups/5/epics/11/notes/1
+```
+
+### Create new epic note
+
+Creates a new note for a single epic. Epic notes are comments users can post to an epic.
+If you create a note where the body only contains an Award Emoji, you'll receive this object back.
+
+```
+POST /groups/:id/epics/:epic_id/notes
+```
+
+Parameters:
+
+| Attribute | Type           | Required | Description |
+| --------- | -------------- | -------- | ----------- |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |
+| `epic_id` | integer | yes  | The ID of an epic |
+| `body`    | string  | yes  | The content of a note |
+
+```bash
+curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/snippet/11/notes?body=note
+```
+
+### Modify existing epic note
+
+Modify existing note of an epic.
+
+```
+PUT /groups/:id/epics/:epic_id/notes/:note_id
+```
+
+Parameters:
+
+| Attribute | Type           | Required | Description |
+| --------- | -------------- | -------- | ----------- |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |
+| `epic_id` | integer | yes  | The ID of an epic |
+| `note_id` | integer | yes  | The ID of a note |
+| `body`    | string  | yes  | The content of a note |
+
+```bash
+curl --request PUT --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/projects/5/snippet/11/notes?body=note
+```
+
+### Delete an epic note
+
+Deletes an existing note of an epic.
+
+```
+DELETE /groups/:id/epics/:epic_id/notes/:note_id
+```
+
+Parameters:
+
+| Attribute | Type           | Required | Description |
+| --------- | -------------- | -------- | ----------- |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) |
+| `epic_id` | integer | yes  | The ID of an epic |
+| `note_id` | integer | yes  | The ID of a note |
+
+```bash
+curl --request DELETE --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/groups/5/epics/52/notes/1659
+```