style with `...`

README.md

@@ -104,7 +104,7 @@ You can access classes from the site you are printing for styling.
 From the puppeteer documentation:
 
 headerTemplate <string> HTML template for the print header. Should be valid HTML markup with following classes used to inject printing values into them:
- * date: formatted print date
+ * `date` formatted print date
  * title: document title
  * url: document location
  * pageNumber: current page number