Docs needs to be updated after `:` -> `@` migration

[Shatur]

How can Bevy's documentation be improved?

We mention the inheritance syntax right after we introduce component scenes. But the syntax is changed.

[mrec]

Nitpick, but isn't there a missing word in that screenshot too? Feels like it should be

This means that if you write systems that query for the Player component, they can assume the rest of the scene will be there too!

or maybe

This means that you write systems that query for the Player component, and they can assume the rest of the scene will be there too!