documentation for api method which get labels of a project

doc/api/projects.md

@@ -621,3 +621,29 @@ Parameters:
 +   query (required) - A string contained in the project name
 +   per_page (optional) - number of projects to return per page
 +   page (optional) - the page to retrieve
+
+
+## Labels
+
+### List project labels
+
+Get a list of project labels.
+
+```
+GET /projects/:id/labels
+```
+
+Parameters:
+
++ `id` (required) - The ID or NAMESPACE/PROJECT_NAME of a project
+
+```json
+[
+  {
+    "name":"featute"
+  },
+  {
+    "name": "bug"
+  }
+]
+```