API docs: macros. Standard Documentation Checklist

[AndyGauge]

Fixes #29381
r? @steveklabnik

[rust-highfive]

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[arielb1]

[00:58:58] failures:
[00:58:58] 
[00:58:58] ---- macros.rs - eprint (line 196) stdout ----
[00:58:58] 	error[E0423]: expected function, found macro `eprint`
[00:58:58]  --> macros.rs:4:1
[00:58:58]   |
[00:58:58] 4 | eprint("Error: Could not complete task");
[00:58:58]   | ^^^^^^ did you mean `eprint!(...)`?
[00:58:58] 
[00:58:58] thread 'rustc' panicked at 'couldn't compile the test', /checkout/src/librustdoc/test.rs:280:12
[00:58:58] note: Run with `RUST_BACKTRACE=1` for a backtrace.
[00:58:58] 
[00:58:58] ---- macros.rs - eprintln (line 224) stdout ----
[00:58:58] 	error[E0423]: expected function, found macro `eprint`
[00:58:58]  --> macros.rs:4:1
[00:58:58]   |
[00:58:58] 4 | eprint("Error: Could not complete task");
[00:58:58]   | ^^^^^^ did you mean `eprint!(...)`?
[00:58:58] 
[00:58:58] thread 'rustc' panicked at 'couldn't compile the test', /checkout/src/librustdoc/test.rs:280:12
[00:58:58] 
[00:58:58] 
[00:58:58] failures:
[00:58:58]     macros.rs - eprint (line 196)
[00:58:58]     macros.rs - eprintln (line 224)
[00:58:58] 
[00:58:58] test result: FAILED. 842 passed; 2 failed; 10 ignored; 0 measured; 0 filtered out

[steveklabnik]

@bors: r+ rollup

thank you, this looks great!

[bors]

📌 Commit 80d513a has been approved by steveklabnik