chore: add javascript link filtering to demo

Author: thibaudcolas

public/tests/index.html

@@ -51,7 +51,8 @@ <h1>Draft.js filters – Manual copy/paste tests</h1>
           <a href="/absolute">absolute link</a>,
           <a href="relative">relative link</a>,
           <a href="https://www.example.com/">full URL</a>,
-          <a href="mailto:test@example.com">mailto</a>
+          <a href="mailto:test@example.com">mailto</a>,
+          <a href="javascript:alert('Hello, world!')">javascript</a>
         </p>
         <p>Image:</p>
         <img src="../word-toolbars-overload.jpg" />