Rendering a breadcrumb with menu in Twig

Hi,

I am trying the render the following in twig and I wanted to get some feedback on what would make most sense.

A breadcrumb needs to be rendered and the last item (current) is a dropdown toggle which opens a list of the parents children.

What I do right now is render a custom breadcrumb and call a knp menu at the end item but it maybe the cleaner to do this all in one template? Does anyone have any recommendations of how I could do this in one template?

The menu tree:
```html
Root
|- Item 1
|- SubItem 1
|- SubItem 2
|- 2ndSubItem 1
|- 2ndSubItem 2
|- SubItem 3
|- Item 2
|- Item 3
|- Item 4
```

Output (when at SubItem 1):
```html

1. Item 1


2. 
   SubItem 1
   
   
   
   • Item 1
   
   
   • Item 2
   
   
   • Item 3
   
   
   • Item 4
   
   
   
   

Output (when at 2ndSubItem 1):
```html

1. Item 1


2. SubItem 2


3. 
   2ndSubItem 1
   
   
   
   • SubItem 1
   
   
   • SubItem 2
   
   
   • SubItem 3
   
   
   
   

Start by reviewing the Twig rendering approach described in the issue, including the menu tree and both requested HTML outputs. Determine whether KnpMenu can represent a breadcrumb whose current item opens its siblings or children, and define the desired template behavior before attempting an implementation.

Written by the indexing model from the issue text.