Above that, I'd love to see "Trait implementations" section completely reimagined (in general, since both rustdoc and this concept show it in the same way).
The trait section shows so much detail that it misses the forest for the trees. It may display 20 versions of impl<something> Extend<something> for Type<something>, each time with duplicate description of the fn extend, but what it's really trying to say is that the type has an .extend() method that works with several types of parameters.
And there are special traits Ord/Eq/Add/Sub/Mul/Shr which are not important for their own methods, but for what they enable for their type. So maybe they should be handled differently, with a note such as "This type can be compared and used with the following arithmetic operators…".
Similarly with IntoIterator, instead of displaying the trait description, which is more of an implementation detail, it could be replaced with a more concise note along the lines of "This is a container which can be iterated".