Update homepage title

Summary:
It's currently a lower-case "index" which looks a bit off. :)

{F235813923}

Reviewed By: mweststrate

Differential Revision: D21324972

fbshipit-source-id: 6b75b23aa0122e2db08f7532205b6e07758155fc

website/src/pages/index.js

@@ -13,7 +13,7 @@ import useBaseUrl from '@docusaurus/useBaseUrl';
 
 export default function Index() {
   return (
-    <Layout title="index">
+    <Layout title="Extensible mobile app debugger">
       <div>
         <div className="splash">
           <div className="content">