Update API Reference

API-Reference.md

@@ -55,6 +55,28 @@ List all departments.
 ]
 ```
  
+#### `GET /department/`
+ 
+Getting department by identifier.
+ 
+**Response:**
+```json
+[
+  { "code": "ENG"},
+]
+
+[
+  { "name": "Marketing"},
+]
+
+
+[
+  { "cost_center": "CC-1100"},
+]
+```
+ 
+
+
 #### `DELETE /departments/delete`
  
 **Request body:**