Support for <remarks> tag

[eduxavier]

The project already make use of summary tag which has a quick overview over the types and members.

The remarks tag is also important because it supplements the information about those types and members.

I don't know how to visually present this information, can you consider about use it or even provide full support for xml document standards?

https://docs.microsoft.com/en-us/dotnet/csharp/codedoc#remarks