doc: add missing metadata for recursive mkdir

PR-URL: #22949
Refs: #21875
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

doc/api/fs.md

@@ -2143,6 +2143,10 @@ Synchronous lstat(2).
 <!-- YAML
 added: v0.1.8
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/21875
+    description: The second argument can now be an `options` object with
+                 `recursive` and `mode` properties.
   - version: v10.0.0
     pr-url: https://github.com/nodejs/node/pull/12562
     description: The `callback` parameter is no longer optional. Not passing
@@ -2184,6 +2188,10 @@ See also: mkdir(2).
 <!-- YAML
 added: v0.1.21
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/21875
+    description: The second argument can now be an `options` object with
+                 `recursive` and `mode` properties.
   - version: v7.6.0
     pr-url: https://github.com/nodejs/node/pull/10739
     description: The `path` parameter can be a WHATWG `URL` object using `file:`