doc: add metadata about ecdh curve options

- DEFAULT_ECDH_CURVE default changed to 'auto' for 10.0.0
- ecdhCurve parameter allowed multiple values and 'auto' from 9.0.0

PR-URL: https://github.com/nodejs/node/pull/25502


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>