docs: merge API reference table, fix descriptions, add markdownlint

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: nanotaboada

.markdownlint.json

@@ -0,0 +1,6 @@
+{
+  "MD013": false,
+  "MD024": {
+    "siblings_only": true
+  }
+}

README.md

@@ -141,26 +141,17 @@ Interactive API documentation is available via Swagger UI at `https://localhost:
 
 > 💡 Swagger documentation is only available in development mode for security reasons.
 
-**Quick Reference:**
-
-- `GET /players` - List all players
-- `GET /players/{id:Guid}` - Get player by ID (requires authentication)
-- `GET /players/squadNumber/{squadNumber:int}` - Get player by squad number
-- `POST /players` - Create new player
-- `PUT /players/squadNumber/{squadNumber:int}` - Update player
-- `DELETE /players/squadNumber/{squadNumber:int}` - Remove player
-- `GET /health` - Health check
-
-**Response Codes:**
-
-| Code | Description |
-| ---- | ----------- |
-| `200 OK` | Successful GET/PUT |
-| `201 Created` | Successful POST |
-| `204 No Content` | Successful DELETE |
-| `400 Bad Request` | Validation failed |
-| `404 Not Found` | Player not found |
-| `409 Conflict` | Duplicate squad number on POST |
+| Method | Endpoint | Description | Status |
+| ------ | -------- | ----------- | ------ |
+| `GET` | `/players` | List all players | `200 OK` |
+| `GET` | `/players/{id:Guid}` | Get player by ID *(requires authentication)* | `200 OK` |
+| `GET` | `/players/squadNumber/{squadNumber:int}` | Get player by squad number | `200 OK` |
+| `POST` | `/players` | Create new player | `201 Created` |
+| `PUT` | `/players/squadNumber/{squadNumber:int}` | Update player by squad number | `200 OK` |
+| `DELETE` | `/players/squadNumber/{squadNumber:int}` | Remove player by squad number | `204 No Content` |
+| `GET` | `/health` | Health check | `200 OK` |
+
+Error codes: `400 Bad Request` (validation failed) · `404 Not Found` (player not found) · `409 Conflict` (duplicate squad number on `POST`)
 
 For complete endpoint documentation with request/response schemas, explore the [interactive Swagger UI](https://localhost:9000/swagger/index.html).