Docs: Vec<T>'s contents being contiguous could be a little more clear

[niconii]

At the moment, Vec<T>'s module and type doc pages don't quite make it clear that its contents are in fact contiguous. They imply it in several places...

Vectors have O(1) indexing, amortized O(1) push (to the end) and O(1) pop (from the end).

Most fundamentally, Vec is and always will be a (pointer, capacity, length) triplet. No more, no less.

...but it would be better to make it more clear. In addition, Vec<T>'s documentation refers to it as a "growable list type", which could be misleading in light of this; "list" is more often used to mean a linked list.

Perhaps something like one of these would be better as the description line:

A contiguous growable list type with heap-allocated contents, written Vec<T> but pronounced 'vector.'

A growable array type with heap-allocated contents, written Vec<T> but pronounced 'vector.'

[GuillaumeGomez]

A more global description is a nice idea. However, keeping the original text is also a nice thing, it's appreciated to have algorithm's complexity. So from my point of view, this would be perfect:

A contiguous growable list type with heap-allocated contents, written Vec but pronounced 'vector.'

A growable array type with heap-allocated contents, written Vec but pronounced 'vector.'

Vectors have O(1) indexing, amortized O(1) push (to the end) and O(1) pop (from the end).

[steveklabnik]

part of #29380