add support for Open Graph Protocol meta tags

[unmonoqueteclea]

Now, generated pages will contain some <meta> tags following the Open Graph Protocol. Many websites (such as Twitter, Facebook, Slack, Telegram, etc) use that protocol to generate url previews.

We are adding:

• og:title: From #+TITLE
• og:description: From #+DESCRIPTION
• og:type: Is always article
• <meta name="twitter:card" content="summary_large_image">: Used by Twitter/X to show a nice card for the url preview
• og:image: User can configure one using the new #+IMAGE property, or set a default with org-static-blog-image

I am using this feature in my blog

This is just a first version, and I am happy to discuss possible improvements.

[bastibe]

As far as I can tell, this is missing the mandatory og:url entry.

[bastibe]

Thank you for the pull request! I like it.

However, I am worried that some users may find it off-putting to include what accounts to facebook metadata into their personal blogs. I would therefore prefer an option to disable the og:... meta-tag generation, and make it opt-in.

[unmonoqueteclea]

As far as I can tell, this is missing the mandatory og:url entry.

Done!

[unmonoqueteclea]

Thank you for the pull request! I like it.

However, I am worried that some users may find it off-putting to include what accounts to facebook metadata into their personal blogs. I would therefore prefer an option to disable the og:... meta-tag generation, and make it opt-in.

Done!

[bastibe]

Looks good to me!

Is this ready to merge from your end?

[unmonoqueteclea]

Absolutely!

[bastibe]

Thank you very much for your contribution! I love it!