doc: add changelogs for url

PR-URL: #11489
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Italo A. Casas <me@italoacasas.com>

Author: addaleax

doc/api/url.md

@@ -262,6 +262,18 @@ object.
 ## url.resolve(from, to)
 <!-- YAML
 added: v0.1.25
+changes:
+  - version: v6.6.0
+    pr-url: https://github.com/nodejs/node/pull/8215
+    description: The `auth` fields are now kept intact when `from` and `to`
+                 refer to the same host.
+  - version: v6.5.0, v4.6.2
+    pr-url: https://github.com/nodejs/node/pull/8214
+    description: The `port` field is copied correctly now.
+  - version: v6.0.0
+    pr-url: https://github.com/nodejs/node/pull/1480
+    description: The `auth` fields is cleared now the `to` parameter
+                 contains a hostname.
 -->
 
 * `from` {String} The Base URL being resolved against.