Fix Get started and Learn more button links on the index page

Summary:
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**Summary**

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Fixes facebook#114 Learn more button links to a page that doesn't exist. This fixes both Learn more and Getting Starting buttons according to the comment in the issue.

**Test plan**

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Closes facebook#121

Differential Revision: D6719758

Pulled By: rafeca

fbshipit-source-id: 9647affacdda3c04b1e180fa95c1da28a51c0926

website/pages/en/index.js

@@ -79,7 +79,7 @@ class HomeSplash extends React.Component {
                         siteConfig.baseUrl +
                         'docs/' +
                         this.props.language +
-                        '/api.html'
+                        '/getting-started.html'
                       }
                     >
                       <translate>Get Started</translate>
@@ -89,7 +89,7 @@ class HomeSplash extends React.Component {
                         siteConfig.baseUrl +
                         'docs/' +
                         this.props.language +
-                        '/snapshot-testing.html'
+                        '/api.html'
                       }
                     >
                       <translate>Learn More</translate>