Remove mention of missing_doc_code_examples lint from rustdoc book

[GuillaumeGomez]

Fixes #109601.

r? @notriddle

[notriddle]

Please add it to the unstable features section? https://doc.rust-lang.org/nightly/rustdoc/unstable-features.html

[GuillaumeGomez]

I added it into the unstable features.

[notriddle]

@bors r+ rollup

[bors]

📌 Commit b85fcf5 has been approved by notriddle

It is now in the queue for this repository.

[bors]

⌛ Testing commit b85fcf5 with merge efccc435ff418d6f3198b47d532aa4a4de93adde...

[bors]

💔 Test failed - checks-actions

[rust-log-analyzer]

A job failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[GuillaumeGomez]

@bors retry

[bors]

⌛ Testing commit b85fcf5 with merge 4f87a63...

[bors]

☀️ Test successful - checks-actions
Approved by: notriddle
Pushing 4f87a63 to master...

[bors]

☀️ Test successful - checks-actions
Approved by: notriddle
Pushing 4f87a63 to master...

[rust-timer]

Finished benchmarking commit (4f87a63): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.8%	[-3.2%, -2.5%]	2
All ❌✅ (primary)	-	-	0

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.0%	[2.0%, 2.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0