Needs a link on https://fsharp.org/specs/language-spec/

[nojaf]

Wrong repo, I know, but feel like shouting somewhere.
We should add a link from https://fsharp.org/specs/language-spec/ to https://fsharp.github.io/fslang-spec/

[Martin521]

Completed by fsharp/fsharp.org#1014

[nojaf]

Thanks 😊