Add canonical state renderable to provide default implementation for

renderables to be trivially state renderable

src/Html/Renderables/CanonicalStateRenderable.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Erusev\Parsedown\Html\Renderables;
+
+use Erusev\Parsedown\Html\Renderable;
+use Erusev\Parsedown\State;
+
+trait CanonicalStateRenderable
+{
+    /**
+     * @return Renderable
+     */
+    public function renderable(State $State)
+    {
+        return $this;
+    }
+}

src/Html/Renderables/Text.php

@@ -7,6 +7,8 @@ use Erusev\Parsedown\Html\Sanitisation\Escaper;
 
 final class Text implements Renderable
 {
+    use CanonicalStateRenderable;
+
     /** @var string */
     private $text;