Missing union-types-spec and many bad links to md

[som-snytt]

Compiler version

3.6 reference

Expectation

https://dotty.epfl.ch/docs/reference/new-types/union-types.html

links to

https://dotty.epfl.ch/docs/reference/new-types/union-types-spec.html

via "more details"

but

https://www.scala-lang.org/files/archive/api/current/docs/docs/reference/new-types/union-types.html

does not.

Now I see that various links are not to *.html targets.

https://www.scala-lang.org/files/archive/api/current/docs/docs/reference/new-types/union-types-spec.md

including forward/back navigation, but not all.

Edit: this is so severe, it must be an interaction with my (Firefox) browser settings, which aren't the most privacy-enhancing but also not lax. This may be a "won't fix" but anyway will document the limitation (which I won't test at the moment by mucking with my browser settings).