Simplify hero credential card example

Drop the "river ·" login-name prefix in front of the example
passphrase -- it read as an unexplained, unlabeled extra word rather
than a distinct login name, and the separator dot didn't make the
distinction clear either. The card already says "One credential";
showing just the passphrase matches that label with nothing left to
be confused about.

packages/demo/public/index.html

@@ -48,7 +48,7 @@
           </span>
           <div>
             <div class="cc-label">One credential</div>
-            <div class="cc-name">river&thinsp;·&thinsp;spry cozily amber hunting humming varying</div>
+            <div class="cc-name">spry cozily amber hunting humming varying</div>
           </div>
         </div>
         <div class="cc-id">npub1a3x…f92e</div>