Rust Reference page title issues

[cpmsmith]

Documentation style bug

Summary

A few different things around page titles for The Rust Reference:

1. All page titles in the nav begin with ..
2. Page titles in the nav don't match the title when viewing them, e.g. Grouped expressions shows .. The Rust Reference, and Panic shows .. The panic_handler attribute
3. Anchor IDs, e.g. [expr.paren] show up as headings before the actual page heading

May be related to #2510 or its fix

Actual style

Many pages, including: https://devdocs.io/rust/reference/expressions/grouped-expr

Expected style

https://doc.rust-lang.org/reference/expressions/grouped-expr.html#r-expr.paren

[cpmsmith]

Oh also, a couple of pages in the Rust Guide ("the book") have the same .. problem, which I think messes up the sorting within the Guide (note 21.03 above 00.00)

[spamguy]

I can work on this.

[cpmsmith]

@spamguy

I can work on this.

I actually got around to it in #2569. However there is still some unusual stuff going on with the std:: stuff as well, where almost everything is getting put in the std type, even when it should be in some more specific module, e.g. std::process::abort and std::intrinsics::abort are both labelled std::abort, meanwhile std::intrinsics is empty:

[spamguy]

Nice. I'll leave you to it then.