[Uid] Mentioned the Uuid::NAMESPACE_* constants

Author: javiereguiluz

components/uid.rst

@@ -53,11 +53,22 @@ to create each type of UUID::
     $uuid = Uuid::v3($namespace, $name); // $uuid is an instance of Symfony\Component\Uid\UuidV3
     $uuid = Uuid::v5($namespace, $name); // $uuid is an instance of Symfony\Component\Uid\UuidV5
 
+    // the namespaces defined by RFC 4122 are available as constants
+    // (see https://tools.ietf.org/html/rfc4122#appendix-C)
+    $uuid = Uuid::v3(Uuid::NAMESPACE_DNS, $name);
+    $uuid = Uuid::v3(Uuid::NAMESPACE_URL, $name);
+    $uuid = Uuid::v3(Uuid::NAMESPACE_OID, $name);
+    $uuid = Uuid::v3(Uuid::NAMESPACE_X500, $name);
+
     // UUID type 6 is not part of the UUID standard. It's lexicographically sortable
     // (like ULIDs) and contains a 60-bit timestamp and 63 extra unique bits.
     // It's defined in http://gh.peabody.io/uuidv6/
     $uuid = Uuid::v6(); // $uuid is an instance of Symfony\Component\Uid\UuidV6
 
+.. versionadded:: 5.3
+
+    The ``Uuid::NAMESPACE_*`` constants were introduced in Symfony 5.3.
+
 If your UUID is generated by another system, use the ``fromString()`` method to
 create an object and make use of the utilities available for Symfony UUIDs::