Examples page for the docs

[halfnelson]

We should add an examples page that shows off open source applications made with Svelte Native. It would contain items such as

• https://github.com/halfnelson/svelte-native-realworld
• https://github.com/halfnelson/svelte-native-hackernews
• https://github.com/halfnelson/svelte-native-grocery
• https://github.com/halfnelson/svelte-native-test-app

It should encourage users to contribute a PR with a link to their app

[halfnelson]

added to home page