Detect extra "base indentation" in Rust code blocks in docs #15025
Description
What it does
For Rust code blocks, and for code blocks in many other languages, it is very likely that extra indentation is not indented if it is applied across the entire contents of the code block, e.g. an extra space on all lines (or even just all non-empty lines).
Having said that, when/if rustfmt stabilizes formatting code blocks in documentation, this lint may not be needed anymore.
Possibly related, at least implementation-wise: #15023 and #15024.
Advantage
- More consistency in docs.
- Less time spent by reviewers.
Drawbacks
No response
Example
/// ```
/// fn f() {}
/// ```
Should be written as:
/// ```
/// fn f() {}
/// ```