Rollup merge of rust-lang#66465 - mulimoen:fix_lifetime_elision_not_shown, r=rkruppe

add missing 'static lifetime in docs

Author: JohnTitor

src/libstd/keyword_docs.rs

@@ -126,7 +126,7 @@ mod break_keyword { }
 /// look like this:
 ///
 /// ```rust
-/// const WORDS: &str = "hello rust!";
+/// const WORDS: &'static str = "hello rust!";
 /// ```
 ///
 /// Thanks to static lifetime elision, you usually don't have to explicitly use 'static: