add output of File::mime() example
@@ -73,7 +73,7 @@ The **is** method does not simply check the file extension. The Fileinfo PHP ext
#### Getting the MIME type associated with an extension:
- echo File::mime('gif');
+ echo File::mime('gif'); // outputs 'image/gif'
> **Note:** This method simply returns the MIME type defined for the extension in the **application/config/mimes.php** file.