Fix homepage title (#5838)

* Fix homepage title

Fixed homepage title bug, now the homepage will display the title from `content/index.md` instead of the constant `React`.

* Update index.md

Change title to "React" to keep same

Author: daochouwangu

src/components/Seo.tsx

@@ -53,7 +53,7 @@ export const Seo = withRouter(
     const canonicalUrl = `https://${siteDomain}${
       router.asPath.split(/[\?\#]/)[0]
     }`;
-    const pageTitle = isHomePage ? 'React' : title + ' – React';
+    const pageTitle = isHomePage ? title : title + ' – React';
     // Twitter's meta parser is not very good.
     const twitterTitle = pageTitle.replace(/[<>]/g, '');
     return (

src/content/index.md

@@ -1,6 +1,6 @@
 ---
 id: home
-title: React – The library for web and native user interfaces
+title: React
 permalink: index.html
 ---