Update index.html

Let's build added

Author: epsaul

index.html

@@ -54,6 +54,16 @@ <h2>Explore Further</h2>
     <li><a href="colophon.html">Colophon: Behind the Design</a></li>
   </ul>
 </section>
+<section class="lets-build">
+  <h2>Let’s Build</h2>
+  <ul>
+    <li><a href="/primers/flipflop-vco.html">Primitive VCO: Flip-Flop to Voltage-Controlled Oscillator</a></li>
+    <li><a href="/primers/opamp-mixer.html">Op-Amp Mixer: Summing Signals with Elegance</a></li>
+    <li><a href="/primers/passive-filter.html">Passive Filter: Sculpting Tone with Simplicity</a></li>
+    <li><a href="/primers/lfo-from-vco.html">LFO from VCO: Slowing the Pulse, Shaping the Flow</a></li>
+  </ul>
+  <p class="tagline">Hands-on modules for poetic synthesis — minimal parts, maximal meaning.</p>
+</section>
 
 
     <section>