Add title to note box.

Co-authored-by: Marcos Cáceres <[email protected]>

Author: mgiuca

index.html

@@ -822,7 +822,7 @@ <h3>
             fingerprinting/privacy sensitive information that the user might
             not be aware of.
           </p>
-          <p class="note">
+          <p class="note" title="Don't add identifiers to start URLs">
             It is bad practice for a developer to use the [=start URL=]
             to include information that uniquely identifies a user, as it would
             represent a fingerprint that is not cleared when the user clears