Home page: a section on Signals (#254)

Drawn in CSS like DeadAir's: the noise fades and the three items about
the words listened for stay lit. No screenshot, since one would need a
TypeSafe key on the scratch server.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

site/index.html

@@ -105,6 +105,30 @@
       </figure>
     </div>
 
+    <!-- Signals: every item from every feed is noise until the words someone listens for pick
+         a few out. CSS only, as DeadAir's. -->
+    <div class="feature">
+      <div class="say">
+        <h3>Pick the signal out of the noise</h3>
+        <p>Make a Signal with the words to listen for, and a sentence saying what you mean if the words are not enough. iPX reads everything your podcasts and blogs bring in and keeps what is about it in a list of its own, so one subject is in one place however many feeds it turns up in. Signals need a key of your own from <a href="https://typesafe.ai">typesafe.ai</a>.</p>
+      </div>
+      <figure class="frame signals" role="img" aria-label="A list of items from many feeds, most fading into the noise, while the three about the words listened for stay lit.">
+        <div class="tune" aria-hidden="true">
+          <p class="for">Listening for <b>rockets</b>, <b>launch</b>, <b>orbit</b></p>
+          <ul>
+            <li class="n"><i style="width:62%"></i></li>
+            <li class="s">What it takes to stay in orbit</li>
+            <li class="n"><i style="width:48%"></i></li>
+            <li class="n"><i style="width:70%"></i></li>
+            <li class="s">A week at the launch site</li>
+            <li class="n"><i style="width:55%"></i></li>
+            <li class="n"><i style="width:40%"></i></li>
+            <li class="s">Why the second stage came down early</li>
+          </ul>
+        </div>
+      </figure>
+    </div>
+
     <div class="feature">
       <div class="say">
         <h3>See what others listen to</h3>