Merge pull request #415 from coriolinus/simple-linked-list-fix-hints-md

simple-linked-list: fix hints.md

Author: coriolinus

exercises/simple-linked-list/.meta/hints.md

@@ -17,7 +17,7 @@ struct Node<T> {
 ```
 `data` contains the stored data, and `next` points to the following node (if available) or None.  
 
-### Why Option<__Box__<Node<T>>> and not just Option<Node<T>>?
+### Why `Option<Box<Node<T>>>` and not just `Option<Node<T>>`?
 Try it on your own. You will get the following error.
 
 ```
@@ -27,8 +27,7 @@ Try it on your own. You will get the following error.
 |     next: Option<Node<T>>,
 |     --------------------- recursive without indirection
  ```
- 
+
  The problem is that at compile time the size of next must be known.
  Since `next` is recursive ("a node has a node has a node..."), the compiler does not know how much memory is to be allocated.
  In contrast, [Box](https://doc.rust-lang.org/std/boxed/) is a heap pointer with a defined size.
- 

exercises/simple-linked-list/README.md

@@ -40,7 +40,7 @@ struct Node<T> {
 ```
 `data` contains the stored data, and `next` points to the following node (if available) or None.  
 
-### Why Option<__Box__<Node<T>>> and not just Option<Node<T>>?
+### Why `Option<Box<Node<T>>>` and not just `Option<Node<T>>`?
 Try it on your own. You will get the following error.
 
 ```
@@ -50,11 +50,11 @@ Try it on your own. You will get the following error.
 |     next: Option<Node<T>>,
 |     --------------------- recursive without indirection
  ```
- 
+
  The problem is that at compile time the size of next must be known.
  Since `next` is recursive ("a node has a node has a node..."), the compiler does not know how much memory is to be allocated.
  In contrast, [Box](https://doc.rust-lang.org/std/boxed/) is a heap pointer with a defined size.
- 
+
 
 ## Rust Installation