VS Code Intellisense reporting `Undefined method 'insertBefore'`

[n18l]

I've noticed that my IDE (VS Code) has been highlighting the insertBefore method as unknown despite the fact that it works as expected. I took a quick peek and found that it's likely just a matter of documentation.

An AbstractNode's parent is documented as being an InnerNode (or null):

php-html-parser/src/PHPHtmlParser/Dom/Node/AbstractNode.php

Lines 44 to 49 in c116346

	/**
	* Contains the parent Node.
	*
	* @var ?InnerNode
	*/
	protected $parent;

But the getParent method is documented as returning an AbstractNode:

php-html-parser/src/PHPHtmlParser/Dom/Node/AbstractNode.php

Lines 154 to 162 in c116346

	/**
	* Returns the parent of node.
	*
	* @return AbstractNode
	*/
	public function getParent()
	{
	return $this->parent;
	}

I'm not 100% sure what the documented return types should be, but at the very least they don't seem to match here, which is ultimately causing Intellisense to interpret something as broken.

Thanks a ton for this great library!

[paquettg]

I have updated the getParent method to return the innerNode, which is accurate.