feat: Add API contract for delete task by ID [todo-backend]

todo-backend/README.md

@@ -58,12 +58,13 @@
 
 ## **Requests**
 
-|                    Route                     |            Description            |
-| :------------------------------------------: | :-------------------------------: |
-|        [GET /v1/tasks](#get-v1tasks)         | Return all tasks with pagination  |
-|       [POST /v1/tasks](#post-v1tasks)        |         Creates new task          |
-|       [GET /v1/health](#get-v1health)        |       Health check endpoint       |
-| [GET /v1/tasks/{taskId}](#get-v1taskstaskid) | Retrieves a single task by its ID |
+|                       Route                        |            Description            |
+| :------------------------------------------------: | :-------------------------------: |
+|           [GET /v1/tasks](#get-v1tasks)            | Return all tasks with pagination  |
+|          [POST /v1/tasks](#post-v1tasks)           |         Creates new task          |
+|          [GET /v1/health](#get-v1health)           |       Health check endpoint       |
+|    [GET /v1/tasks/{taskId}](#get-v1taskstaskid)    | Retrieves a single task by its ID |
+| [DELETE /v1/tasks/{taskId}](#delete-v1taskstaskid) |      Deletes a specific task      |
 
 ## **GET /v1/tasks**
 
@@ -274,6 +275,76 @@ Creates a new task
     }
     ```
 
+## **DELETE /v1/tasks/{taskId}**
+
+Deletes a task with the given `task_id`.
+
+- **Params**
+
+  - `task_id`: The unique identifier of the task (as a path parameter)
+
+- **Success Response:**
+
+  - **Code:** 204
+  - **Content:** None
+
+- **Error Responses:**
+
+  - **Code:** 400
+
+    - **Reason:** Invalid `task_id` format
+    - **Content:**
+      ```json
+      {
+        "statusCode": 400,
+        "message": "Please enter a valid Task ID format.",
+        "errors": [
+          {
+            "source": {
+              "path": "task_id"
+            },
+            "title": "Validation Error",
+            "detail": "Please enter a valid Task ID format."
+          }
+        ]
+      }
+      ```
+
+  - **Code:** 404
+
+    - **Reason:** Task with the given `task_id` was not found
+    - **Content:**
+      ```json
+      {
+        "statusCode": 404,
+        "message": "Task with ID <task_id> not found.",
+        "errors": [
+          {
+            "source": {
+              "path": "task_id"
+            },
+            "title": "Resource Not Found",
+            "detail": "Task with ID <task_id> not found."
+          }
+        ]
+      }
+      ```
+
+  - **Code:** 500
+    - **Reason:** Internal server error
+    - **Content:**
+      ```json
+      {
+        "statusCode": 500,
+        "message": "An unexpected error occurred",
+        "errors": [
+          {
+            "detail": "Internal server error"
+          }
+        ]
+      }
+      ```
+
 ## **GET /v1/health**
 
 Health check endpoint