Update Rust crate mdbook to ^0.4.35

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
mdbook	dependencies	patch	^0.4.34 -> ^0.4.35

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Release Notes

rust-lang/mdBook (mdbook)

### [`v0.4.35`](https://togithub.com/rust-lang/mdBook/blob/HEAD/CHANGELOG.md#mdBook-0435) [Compare Source](https://togithub.com/rust-lang/mdBook/compare/v0.4.34...v0.4.35) [v0.4.34...v0.4.35](https://togithub.com/rust-lang/mdBook/compare/v0.4.34...v0.4.35) ##### Added - Added the `book.text-direction` setting for explicit support for right-to-left languages. [#​1641](https://togithub.com/rust-lang/mdBook/pull/1641) - Added `rel=prefetch` to the "next" links to potentially improve browser performance. [#​2168](https://togithub.com/rust-lang/mdBook/pull/2168) - Added a `.warning` CSS class which is styled for displaying warning blocks. [#​2187](https://togithub.com/rust-lang/mdBook/pull/2187) ##### Changed - Better support of the sidebar when JavaScript is disabled. [#​2175](https://togithub.com/rust-lang/mdBook/pull/2175)

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