doc: Fix a few small issues

* A few typos around generic types (`;` vs `,`)
* Use inline code formatting for code fragments
* One instance of wrong wording

library/alloc/src/collections/vec_deque/mod.rs

@@ -2541,7 +2541,7 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// The deque is assumed to be partitioned according to the given predicate.
     /// This means that all elements for which the predicate returns true are at the start of the deque
     /// and all elements for which the predicate returns false are at the end.
-    /// For example, [7, 15, 3, 5, 4, 12, 6] is a partitioned under the predicate x % 2 != 0
+    /// For example, `[7, 15, 3, 5, 4, 12, 6]` is partitioned under the predicate `x % 2 != 0`
     /// (all odd numbers are at the start, all even at the end).
     ///
     /// If the deque is not partitioned, the returned result is unspecified and meaningless,

library/core/src/array/mod.rs

@@ -69,7 +69,7 @@ where
 /// if any element creation was unsuccessful.
 ///
 /// The return type of this function depends on the return type of the closure.
-/// If you return `Result<T, E>` from the closure, you'll get a `Result<[T; N]; E>`.
+/// If you return `Result<T, E>` from the closure, you'll get a `Result<[T; N], E>`.
 /// If you return `Option<T>` from the closure, you'll get an `Option<[T; N]>`.
 ///
 /// # Arguments
@@ -522,7 +522,7 @@ impl<T, const N: usize> [T; N] {
     /// return an array the same size as `self` or the first error encountered.
     ///
     /// The return type of this function depends on the return type of the closure.
-    /// If you return `Result<T, E>` from the closure, you'll get a `Result<[T; N]; E>`.
+    /// If you return `Result<T, E>` from the closure, you'll get a `Result<[T; N], E>`.
     /// If you return `Option<T>` from the closure, you'll get an `Option<[T; N]>`.
     ///
     /// # Examples

library/core/src/iter/traits/iterator.rs

@@ -2734,7 +2734,7 @@ pub trait Iterator {
     /// the first true result or the first error.
     ///
     /// The return type of this method depends on the return type of the closure.
-    /// If you return `Result<bool, E>` from the closure, you'll get a `Result<Option<Self::Item>; E>`.
+    /// If you return `Result<bool, E>` from the closure, you'll get a `Result<Option<Self::Item>, E>`.
     /// If you return `Option<bool>` from the closure, you'll get an `Option<Option<Self::Item>>`.
     ///
     /// # Examples

library/core/src/slice/mod.rs

@@ -3795,7 +3795,7 @@ impl<T> [T] {
     /// The slice is assumed to be partitioned according to the given predicate.
     /// This means that all elements for which the predicate returns true are at the start of the slice
     /// and all elements for which the predicate returns false are at the end.
-    /// For example, [7, 15, 3, 5, 4, 12, 6] is a partitioned under the predicate x % 2 != 0
+    /// For example, `[7, 15, 3, 5, 4, 12, 6]` is partitioned under the predicate `x % 2 != 0`
     /// (all odd numbers are at the start, all even at the end).
     ///
     /// If this slice is not partitioned, the returned result is unspecified and meaningless,