Package should include XML Docs

[tombogle]

Is your feature request related to a problem? Please describe.

In VisualStudio, if I hover over classes or methods in this DLL, the summary is not displayed.

Describe the solution you'd like

Change the packaging so the XML docs are included with the package

Additional context

This was motivated by my investigation into why Wrapper.UnicodeVersion could throw exceptions related to DLL loading problems. I think it would be good to add that information to the XML docs, but that will only be of limited usefulness if the docs are not part of the package.