Update header for elixir circuits libraries

Author: mattludwigs

index.html

@@ -56,7 +56,7 @@ <h3><a href="https://github.com/elixir-circuits/circuits_uart">UART</a></h3>
     <hr class="container">
 
     <div class="container section content js-hex-query-component query-component">
-     <h2 class="header h2 text center">Search</h2>
+     <h2 class="header h2 text center">What uses Elixir Circuits?</h2>
 
 
      <div class="flex-container library-search">