doc: document resolve hook formats

Noticed format: "dynamic" was missing from the docs (it's mentioned later on).

Add "dynamic" to the list of supported formats returned by a custom resolve hook.

Add a table describing the meaning of each format.

Refs: https://github.com/nodejs/node/pull/15445

Checklist

• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

doc

cc. @guybedford, @bmeck