Add setName method to Tag and type to offsetGet

Introduces a setName method to the Tag class for setting the tag name and returning a cloned instance. Also adds a return type to the offsetGet method in Collection for improved type safety.

paquettg#250

Author: mr-chetan

src/PHPHtmlParser/Dom/Node/Collection.php

@@ -134,7 +134,7 @@ public function offsetUnset($offset): void
      * @param  mixed  $offset
      * @return mixed
      */
-    public function offsetGet($offset)
+    public function offsetGet($offset): mixed
     {
         return $this->collection[$offset] ?? null;
     }

src/PHPHtmlParser/Dom/Tag.php

@@ -97,6 +97,16 @@ public function name(): string
         return $this->name;
     }
 
+    /**
+     * Sets the name of this tag.
+     */
+    public function setName(string $name): Tag
+    {
+        $this->name = $name;
+
+        return clone $this;
+    }
+
     /**
      * Sets the tag to be self closing.
      */