fix: typo in ok-stack

src/too-many-lists/ok-stack/iter.md

@@ -217,7 +217,7 @@ impl<'a, T> Iterator for Iter<'a, T> {
 
 现在，我们也许可以自信的编译下试试了：
 ```shell
-cargo build
+> cargo build
 
 error[E0308]: mismatched types
   --> src/second.rs:77:22
@@ -260,7 +260,8 @@ impl<'a, T> Iterator for Iter<'a, T> {
 ```
 
 ```shell
-cargo build
+> cargo build
+
    Compiling lists v0.1.0 (/Users/ABeingessner/dev/temp/lists)
 error[E0515]: cannot return reference to local data `*node`
   --> src/second.rs:77:43
@@ -314,7 +315,8 @@ impl<'a, T> Iterator for Iter<'a, T> {
 ```
 
 ```shell
-cargo build
+> cargo build
+
    Compiling lists v0.1.0 (/Users/ABeingessner/dev/temp/lists)
 error[E0308]: mismatched types
   --> src/second.rs:77:22
@@ -362,7 +364,7 @@ impl<'a, T> Iterator for Iter<'a, T> {
 ```
 
 ```shell
-cargo build
+> cargo build
 ```
 
 🎉 🎉 🎉

src/too-many-lists/ok-stack/itermut.md

@@ -58,6 +58,7 @@ impl<'a, T> Iterator for IterMut<'a, T> {
 
 ```shell
 > cargo build
+
 error[E0596]: cannot borrow `self.head` as mutable, as it is behind a `&` reference
   --> src/second.rs:95:25
    |

src/too-many-lists/ok-stack/peek.md

@@ -46,7 +46,7 @@ pub fn peek(&self) -> Option<&T> {
 ```
 
 ```shell
-cargo build
+> cargo build
 
     Finished dev [unoptimized + debuginfo] target(s) in 0.32s
 ```
@@ -124,7 +124,7 @@ fn peek() {
 这次我们直接匹配出来可变引用 `value`，然后对其修改即可。
 
 ```shell
-cargo test
+> cargo test
 
      Running target/debug/lists-5c71138492ad4b4a
 

src/too-many-lists/ok-stack/type-optimizing.md

@@ -137,7 +137,7 @@ test second::test::basics ... ok
 test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured
 ```
 
-很棒，接下来让我们来解决目前链表最大的问题：只支持 i32 类型的元素值。
+很棒，接下来让我们来解决目前链表最大的问题：只支持 `i32` 类型的元素值。
 
 ## 泛型
 为了让链表支持任何类型的元素，泛型就是绕不过去的坎，首先将所有的类型定义修改为泛型实现：