Made it clearer that issue_id means iid, not id.

doc/api/notes.md

@@ -15,7 +15,7 @@ GET /projects/:id/issues/:issue_id/notes
 Parameters:
 
 - `id` (required) - The ID of a project
-- `issue_id` (required) - The ID of an issue
+- `issue_id` (required) - The IID of an issue (not ID)
 
 ```json
 [
@@ -73,7 +73,7 @@ GET /projects/:id/issues/:issue_id/notes/:note_id
 Parameters:
 
 - `id` (required) - The ID of a project
-- `issue_id` (required) - The ID of a project issue
+- `issue_id` (required) - The IID of a project issue (not ID)
 - `note_id` (required) - The ID of an issue note
 
 ### Create new issue note
@@ -87,7 +87,7 @@ POST /projects/:id/issues/:issue_id/notes
 Parameters:
 
 - `id` (required) - The ID of a project
-- `issue_id` (required) - The ID of an issue
+- `issue_id` (required) - The IID of an issue (not ID)
 - `body` (required) - The content of a note
 - `created_at` (optional) - Date time string, ISO 8601 formatted, e.g. 2016-03-11T03:45:40Z
 
@@ -102,7 +102,7 @@ PUT /projects/:id/issues/:issue_id/notes/:note_id
 Parameters:
 
 - `id` (required) - The ID of a project
-- `issue_id` (required) - The ID of an issue
+- `issue_id` (required) - The IID of an issue (not ID)
 - `note_id` (required) - The ID of a note
 - `body` (required) - The content of a note
 
@@ -120,7 +120,7 @@ Parameters:
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
 | `id` | integer | yes | The ID of a project |
-| `issue_id` | integer | yes | The ID of an issue |
+| `issue_id` | integer | yes | The IID of an issue |
 | `note_id` | integer | yes | The ID of a note |
 
 ```bash