[RFC] [docs] Add Flexbox Examples using the Stack component in the docs

What's the problem? 🤔

If I read the mui system documentation about flexbox, I was expecting to see some examples of the Stack component because it's basically a Box that implements flex, right?
But there are only examples of flexbox implemented with Box.

What are the requirements? ❓

The Stack component should be represented in the Flexbox documentation.

What are our options? 💡

1. Either rewrite the docs using Stack

OR (preferred):

2. Add flexbox examples using Stack and show them first.

Proposed solution 🟢

As said before, I would like to see Stack represented in the docs. Seeing only Box being used might lead to people thinking this is the preferred way of flexbox.
BUT I can also see that the linked documentation is implemented using only Box, which might have been done for a valid reason.
Thats why I am asking for comments on this.

Resources and benchmarks 🔗

No response