Rollup merge of #83662 - ehuss:update-books, r=ehuss

Update books

## reference

4 commits in d10a0af8dca25d9d548ca6a369fd66ad06acb3c9..fd97729e2d82f8b08d68a31c9bfdf0c37a7fd542
2021-03-21 11:14:06 -0700 to 2021-03-28 14:29:19 -0700
- Editorial cleanup on expressions (part 1) (rust-lang/reference#967)
- Update type casts section (rust-lang/reference#961)
- Add missing "?" notion (rust-lang/reference#989)
- Fix typo (rust-lang/reference#988)

## book

8 commits in fc2f690fc16592abbead2360cfc0a42f5df78052..b54090a99ec7c4b46a5203a9c927fdbc311bb1f5
2021-03-05 14:03:22 -0500 to 2021-03-24 11:21:46 -0500
- correct the signature of the `deref` method (rust-lang/book#2658)
- Clarify the immutability of a reference (rust-lang/book#2646)
- Tweak wording around Windows representation of enter
- Ch. 02 note - Enter results in CRLF on Windows (rust-lang/book#2648)
- Added an example of slicing result (rust-lang/book#2649)
- Fix word wrapping, mention dictionary.txt is also in the ci dir
- README: note that spellcheck.sh is in ci directory (rust-lang/book#2652)
- Change someurl.com to example.org (rust-lang/book#2655)

## rust-by-example

12 commits in eead22c6c030fa4f3a167d1798658c341199e2ae..29d91f591c90dd18fdca6d23f1a9caf9c139d0d7
2021-03-04 16:26:43 -0300 to 2021-03-23 09:03:39 -0300
- Unwrap some drinks. (rust-lang/rust-by-example#1431)
- doc(testcase_linked_list): add a little extra note about pattern (rust-lang/rust-by-example#1408)
- Update function name in comment (rust-lang/rust-by-example#1413)
- Fixes minor typo in src/types/cast.md (rust-lang/rust-by-example#1414)
- Add destructuring example to generics new type (rust-lang/rust-by-example#1416)
- update struct.md (rust-lang/rust-by-example#1419)
- fix name from rectangle to Rectangle (rust-lang/rust-by-example#1420)
- Typo "incures" in code comment (rust-lang/rust-by-example#1422)
- Changed impl to use Self::Item (rust-lang/rust-by-example#1425)
- Fix code highlighting in some places (rust-lang/rust-by-example#1427)
- Update multi_bounds.md (rust-lang/rust-by-example#1428)
- Reformulated text for redability (rust-lang/rust-by-example#1429)

## rustc-dev-guide

3 commits in 67ebd4b55dba44edfc351621cef6e5e758169c55..0687daac28939c476df51778f5a1d1aff1a3fddf
2021-03-11 13:36:25 -0800 to 2021-03-28 13:33:56 -0400
- Add notes about nightly rustc version for the rustc-driver examples
- Update rustc-driver-*.rs examples (rust-lang/rustc-dev-guide#1095)
- Fix rust compiler meeting info (rust-lang/rustc-dev-guide#1087)

## embedded-book

1 commits in f61685755fad7d3b88b4645adfbf461d500563a2..d3f2ace94d51610cf3e3c265705bb8416d37f8e4
2021-03-08 01:06:44 +0000 to 2021-03-17 07:53:09 +0000
- Add binary attribute to .jpeg files, closes rust-embedded/book#287  (rust-embedded/book#288)