Update index.md

Author: mbostock

docs/index.md

@@ -100,7 +100,7 @@ toc: false
 </style>
 
 <div class="hero">
-  <h1>The best data apps are built with <em class="red">code.</em></h1>
+  <h1>The best dashboards are built with <em class="red">code.</em></h1>
   <h2>Create fast, beautiful data apps, dashboards, and reports from the command line. Write Markdown, JavaScript, SQL, Python, R… and any language you like. Free and open-source.</h2>
   <div class="cta">
     <pre data-copy>npm init @observablehq</pre>