Update README.md

Author: arrowtype

README.md

@@ -19,6 +19,7 @@ Type-X is a Google Chrome extension that makes it easy and efficient to test loc
 
 - Browse comfortably to experience your own fonts in context, with blazing-fast font injection and a one-click override.
 - Use your local fonts or add custom font files directly to test real web font files – WOFF2 included. (All fonts stay on your own computer, and nothing is uploaded to any server, etc).
+- Test variable fonts, inheriting multiple existing weights and styles from a website, to preview how the weights of that font behave.
 - Take full control over how you apply your fonts with custom CSS selectors and styles.
 - Avoid "tofu" from icon fonts with preset and custom selectors to ignore icon elements.