docs: Update usage example in README

Stranger6667 · Stranger6667 · commit 3a5b6c79b023 · 2020-06-22T16:10:17.000+02:00
diff --git a/README.md b/README.md
@@ -50,7 +50,7 @@ cssinline = "0.1"
 ## Example:
 
 ```rust
-use cssinline
+use css_inline;
 
 const HTML: &str = r#"<html>
 <head>
