doc: unhide resolver spec
It comes up quite a bit that people ask me how to implement the Node.js resolver and they weren't necessarily aware there is a detailed specification available.
If we unhide the specification text I think this will make it clearer to more people that there is a very carefully well-defined resolution algorithm that tooling can follow.
We've moved content out of the esm.md page so that it seems like it adds less bloat too at this point.
I'm open to suggestions re moving this somewhere else, and don't feel too strongly that this should land either if anyone has any concerns about this approach as well.
//cc @nodejs/modules-active-members
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
documentation is changed or added -
commit message follows commit guidelines