add tooltip for EFF DNT Policy llowlist

Author: mneunomne

src/whitelist.html

@@ -31,7 +31,7 @@
                 <label>
                   <span class="input checkbox" disabled>
                     <input id="effListInput" type="checkbox" disabled="disabled"><svg viewBox="0 0 24 24"><path d="M1.73,12.91 8.1,19.28 22.79,4.59"></path></svg></span>
-                    <span><span class="forinput">
+                    <span><span class="forinput" alt="EFF DNT Policy is automatically set if Non-tracking Ads are both NOT hidden, and NOT clicked.">
                       EFF DNT Policy Allowlist‎
                       <a href="https://www.eff.org/dnt-policy" target="_blank">(www.eff.org)</a>
                     </span>