Auto merge of #11430 - TDecking:vec-fmt, r=giraffate

Correctly format `vec!` invocations

The [Rust Style Guide](https://doc.rust-lang.org/nightly/style-guide/expressions.html?highlight=vec#array-literals) says that `vec!` should alwys be used with square brackets, not parenthesis. Within the lint documentation, that rule was violated twice.

changelog: none

clippy_lints/src/methods/mod.rs

@@ -3055,12 +3055,12 @@
     ///
     /// ### Example
     /// ```rust
-    /// vec!(1, 2, 3, 4, 5).resize(0, 5)
+    /// vec![1, 2, 3, 4, 5].resize(0, 5)
     /// ```
     ///
     /// Use instead:
     /// ```rust
-    /// vec!(1, 2, 3, 4, 5).clear()
+    /// vec![1, 2, 3, 4, 5].clear()
     /// ```
     #[clippy::version = "1.46.0"]
     pub VEC_RESIZE_TO_ZERO,

clippy_lints/src/unit_return_expecting_ord.rs

@@ -26,7 +26,7 @@
     ///
     /// ### Example
     /// ```rust
-    /// let mut twins = vec!((1, 1), (2, 2));
+    /// let mut twins = vec![(1, 1), (2, 2)];
     /// twins.sort_by_key(|x| { x.1; });
     /// ```
     #[clippy::version = "1.47.0"]