misc: declare code type in docblocks

src/Attribute/Identifier.php

@@ -12,7 +12,7 @@
  * This attribute can be added to an object property. It will be filled with
  * the iteration key from the source which is used to map the object tree.
  *
- * ```
+ * ```php
  * use CuyZ\Valinor\Attribute\Identifier;
  *
  * final class Foo

src/Mapper/Tree/Message/Formatter/MessageMapFormatter.php

@@ -31,7 +31,7 @@
  *
  * See usage examples below:
  *
- * ```
+ * ```php
  * $formatter = (new MessageMapFormatter([
  *     // Will match if the given message has this exact code
  *     'some_code' => 'new content / previous code was: %1$s',

src/Mapper/Tree/Message/MessagesFlattener.php

@@ -18,7 +18,7 @@
  * flatten all caught errors into a basic array of string that can then easily
  * be used to inform the user of what is wrong.
  *
- * ```
+ * ```php
  * try {
  *     // …
  * } catch(MappingError $error) {

src/Mapper/Tree/Message/NodeMessage.php

@@ -38,7 +38,7 @@ public function __construct(Node $node, Message $message)
      *
      * See usage examples below:
      *
-     * ```
+     * ```php
      * $content = $message->format('the previous code was: %1$s');
      *
      * $content = $message->format(

src/MapperBuilder.php

@@ -32,7 +32,7 @@ public function __construct()
      *
      * Example:
      *
-     * ```
+     * ```php
      * (new \CuyZ\Valinor\MapperBuilder())
      *     ->infer(UuidInterface::class, fn () => MyUuid::class)
      *     ->infer(SomeInterface::class, fn (string $type) => match($type) {