docs(README): fix warning note about import (webpack-contrib#519)

Author: kud

README.md

@@ -169,7 +169,7 @@ To disable `@import` resolving by `css-loader` set the option to `false`
 @import url('https://fonts.googleapis.com/css?family=Roboto');
 ```
 
-> :waning: Use with caution, since this disables resolving for **all** `@import`s, including css modules `composes: xxx from 'path/to/file.css'` feature.
+> _⚠️ Use with caution, since this disables resolving for **all** `@import`s, including css modules `composes: xxx from 'path/to/file.css'` feature._
 
 ### [`modules`](https://github.com/css-modules/css-modules)