[Documentation] Missing open graph metadata

[eladcandroid]

Facebook sharing debugger result:

(https://developers.facebook.com/tools/debug/sharing/?q=https%3A%2F%2Ftypescript.nuxtjs.org%2F)

[kevinmarrec]

@eladcandroid Thanks for pointing this, I think I need to customize some options of Vuepress so it correctly provide open graph metadata.

[kevinmarrec]

https://github.com/webmasterish/vuepress-plugin-autometa may be relevant to use