Update AN0007.md

Author: KThaulow

docs/AN0007.md

@@ -11,11 +11,11 @@
 ### Code with Diagnostic
 
 ```csharp
-string date = DateTime.UtcNow.ToString(""yyyy/MM/dd"");
+string date = DateTime.UtcNow.ToString("yyyy/MM/dd");
 ```
 
 ### Code with Fix
 
 ```csharp
-string date = DateTime.UtcNow.ToString(""yyyy/MM/dd"", CultureInfo.InvariantCulture);
+string date = DateTime.UtcNow.ToString("yyyy/MM/dd", CultureInfo.InvariantCulture);
 ```