Dynamic Open Graph meta tags

[victorienfotsing]

I have made changes to have dynamic og meta tags.
This will help to improve the appearance of shared links.
For example when a link to an author will be share, it will be possible to have on the preview of the link the name of the author and also his picture. This will be the same for books.

I just need read access to create a pull request

[victorienfotsing]

@cs1m0n thanks for the invitation in the repository. I need also read access to be able push any branches