Publish code documentation

[berezovskyi]

mffiedler[CodePlex]
Create some initial API documentation using XML comments

[berezovskyi]

I vaguely remember using https://github.com/EWSoftware/SHFB when I did C# development.

[berezovskyi]

NodaTime uses https://dotnet.github.io/docfx/tutorial/docfx_getting_started.html

[berezovskyi]

Should consider https://dotnet.github.io/docfx/ but it requires .NET 6+ to work.

[berezovskyi]

.NET 6.0+ is now supported, DocFX adoption is unblocked.

[berezovskyi]

Done: https://oslc4net.github.io/