Add documentation for intrinsic types

[BarkingBad]

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[BarkingBad]

@smarter could you take a look is it ok? There is some documentation missing or deprecated since I copied it mostly from scala2 sources. Could you update the docs, as you are more profficient with these intrinsic types. You can commit directly onto my branch or create a separate PR. The only thing left to discuss is the syntax. The classes are from scala package which is mainly from stdlib which keeps wikisyntax. As I mentioned here we could specify which packages are in wikisyntax, but it would enforce us to keep these comments in wikisyntax as well because we share package name

[smarter]

As I mentioned here we could specify which packages are in wikisyntax, but it would enforce us to keep these comments in wikisyntax as well because we share package name

I don't have a particular preference here, but it really seems like supporting the {{{ syntax in the markdown syntax as I suggested in #11728 would be the simplest solution.