Create a Space screen could be simplified and more informative

### Your use case

The Create a space screen has information about spaces located in lots of different places in this screen - why not in one place?
* "Spaces are a new way to group rooms and people at the top (away from all the other UI)
* "To join an existing space, you need an invite" - between the header and the buttons
* "You can change this later" - at the bottom of the screen - change what?

### Have you considered any alternatives?

_No response_

### Additional context

_No response_