RCS1181 wrongly considers that namespaces can have XML comments

[Bergam64]

Product and Version Used:
VS extension Roslynator 2022 v4.12.5

Steps to Reproduce:

• Enable RCS1181 in your .editorconfig file (disabled by default).
• Make sure the containing project is configured to generate documentation files:
  • Open project Properties.
  • Go to page Build -> Output
  • • Generate a file containing API documentation
• Open a C# file and add a comment after the namespace.

Actual Behavior:

namespace MyNamespace // Some comment. <-- RCS1181: Convert comment to documentation comment
{
    /// <summary>
    /// ...
    /// </summary>
    public class Class1
    {
        internal int MyProperty { get; set; }
    }
}

which is wrong, because applying the code fix produces code that triggers a compiler error:

/// <summary> <-- CS1587: XML comment is not placed on a valid language element
/// Some comment.
/// </summary>
namespace MyNamespace
{
    /// <summary>
    /// ...
    /// </summary>
    public class Class1
    {
        internal int MyProperty { get; set; }
    }
}

Expected Behavior:

namespace MyNamespace // Comment. <-- No RCS1181
{
    /// <summary>
    /// ...
    /// </summary>
    public class Class1
    {
        internal int MyProperty { get; set; }
    }
}

You can't add documentation comments to a namespace (see first table here).

Bottom line: RCS1181 should never be reported for comments on namespaces.