fix html not show issue

Author: zbryikt

README.md

@@ -14,17 +14,17 @@ Usage
 
 1. download and include [loading.css](https://raw.githubusercontent.com/loadingio/loading.css/c0b955eba7a7d17819d110ec661e199a2482bdea/preview.gif):
 
-
+```
     <link rel="stylesheet" type="text/css" href="loading.css"/>
-
+```
 
 2. check [loading.css animation gallery](https://loading.io/animation/) for the name of animations you want to use. for example, `ld-spin`.
 
 3. use the name as css class on the element you want to animate:
 
-
+```
     <div class="ld ld-spin"></div>
-
+```
 
 4. for more information, check out [loading.css animation documentation](https://loading.io/animation/).