add category reflection methods

Author: tillkruss

src/Reflection/Reflection.php

@@ -323,11 +323,24 @@ public function isInternal(): bool
         return ! empty($this->getTags('internal'));
     }
 
+    public function hasCategories(): bool
+    {
+        return ! empty($this->getCategories());
+    }
+
     public function hasExamples(): bool
     {
         return ! empty($this->getExamples());
     }
 
+    /**
+     * @return array[]
+     */
+    public function getCategories(): array
+    {
+        return $this->getTags('category');
+    }
+
     /**
      * @return array[]
      */