Add email autocomplete support

More detail on the autocomplete attribute here: https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/autocomplete

Author: Kane Montreuil

index.html

@@ -20,7 +20,7 @@ <h2>Join Us!</h2>
     </div>
   </div>
   <div class="input" id="inputFields">
-    <input required type="email" class="button" id="email" name="invitation[email]" size="30" placeholder="you@example.com">
+    <input required type="email" class="button" id="email" name="invitation[email]" size="30" placeholder="you@example.com" autocomplete="email">
     <input type="submit" class="button" id="submit" value="Invite Me!">
   </div>
 </form>