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: #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>

Author: sam-github

doc/api/tls.md

@@ -1121,6 +1121,10 @@ changes:
   - version: v9.3.0
     pr-url: https://github.com/nodejs/node/pull/14903
     description: The `options` parameter can now include `clientCertEngine`.
+  - version: v9.0.0
+    pr-url: https://github.com/nodejs/node/pull/15206
+    description: The `ecdhCurve` option can now be multiple `':'` separated
+                 curve names or `'auto'`.
   - version: v7.3.0
     pr-url: https://github.com/nodejs/node/pull/10294
     description: If the `key` option is an array, individual entries do not
@@ -1343,6 +1347,10 @@ console.log(tls.getCiphers()); // ['AES128-SHA', 'AES256-SHA', ...]
 ## tls.DEFAULT_ECDH_CURVE
 <!-- YAML
 added: v0.11.13
+changes:
+  - version: v10.0.0
+    pr-url: https://github.com/nodejs/node/pull/16853
+    description: Default value changed to `'auto'`.
 -->
 
 The default curve name to use for ECDH key agreement in a tls server. The