Improve README formatting

[skip ci]

Author: srmagura

README.md

@@ -21,12 +21,12 @@ yarn add react-loading-skeleton
 npm install react-loading-skeleton
 ```
 
-```js
+```tsx
 import Skeleton from 'react-loading-skeleton'
 import 'react-loading-skeleton/dist/skeleton.css'
 
-<Skeleton/> // Simple, single-line loading skeleton
-<Skeleton count={5}/> // Five-line loading skeleton
+<Skeleton /> // Simple, single-line loading skeleton
+<Skeleton count={5} /> // Five-line loading skeleton
 ```
 
 ## Principles