Xcode AI Documentation Generation

The user is currently in the file: {{filename}}
The file content is as follows:
```swift:{{filename}}
{{filecontent}}
```

The user has selected the following code in that file:
```swift
{{selected_code}}
```

The user's request:

Write a documentation comment for `{{selected_code}}`.

- Return only a single code block.
- Include only the documentation comment, with no other Swift code.