squash: Update doc/api/fs.md

Co-authored-by: Antoine du Hamel <[email protected]>

Author: LiviaMedeiros

doc/api/fs.md

@@ -639,7 +639,8 @@ added: v10.0.0
 changes:
   - version: REPLACEME
     pr-url: https://github.com/nodejs/node/pull/41677
-    description: The `string` parameter must be a primitive string.
+    description: The `string` parameter no longer accept objects with an
+                 own `toString` function property.
   - version: v14.12.0
     pr-url: https://github.com/nodejs/node/pull/34993
     description: The `string` parameter will stringify an object with an
@@ -5593,7 +5594,8 @@ added: v0.11.5
 changes:
   - version: REPLACEME
     pr-url: https://github.com/nodejs/node/pull/41677
-    description: The `string` parameter must be a primitive string.
+    description: The `string` parameter no longer accept objects with an
+                 own `toString` function property.
   - version: v14.12.0
     pr-url: https://github.com/nodejs/node/pull/34993
     description: The `string` parameter will stringify an object with an